Besides red and white cells, Texas A&M's Corps runs through Grant Castleberry's blood. So does the Marine Corps, a group he will join when his A&M career is complete.
"I just felt that if I truly wanted to experience what it was to be a true American, that I needed to give back and serve," Castleberry said.
For now, he serves as head yell leader, an honor bestowed on him by his fellow students back in April.
Fast-forward to October, and Arch Yell. When the Ags are on the road, the Corps gets together at the arches on the Quad to hold yell practice, complete with the blaring band.
Grant gets things started with a speech pumping his fellow cadets up for the game against Baylor in Waco. He lambasts the Bears for their introduction of the "Growl Towel," 25,000 free green towels to be given to fans. The head yell leader points out the striking similarity to the famed "12th Man Towel" of A&M.
"They aren't the 12th Man and they aren't Texas A&M and they never will be," he declares, followed shortly by a chorus of whoops. They'll beat the hell out of them, he says (and they do), and practice begins.
"I definitely am glad that God put me where I am now because I can't imagine being happier," Castleberry said. "I love what I do as yell leader."
His job has also given him the chance to learn more about his father, Kelly, a former Corps commander, Ross Volunteer, Earl Rudder Award winner, and Marine Corps pilot. Road games to yell for the Aggies have also turned into story time for Grant, as scores of people tell tales of Kelly Castleberry. The road game prior to the trip up Highway 6 was to Lawrence, Kansas, where an Ag caught up with Grant to talk about Kelly.
"I've met so many people that have told me about my dad," Grant said. "I couldn't imagine a cooler thing than having people tell me about the impact my dad had in their life."
Grant was born in Corpus Christi as Kelly served at the Naval air station there. The Castleberrys would end up in South Carolina at Marine Corps Recruiting Depot Parris Island. Kelly flew the F-4 Phantom in the Marines, a sleak, durable jet that flew for three military branches and over the course of five decades.
It was in his fighter that Kelly Castleberry would spend the last minutes of his life.
"In 1986, my dad was involved in a collision over the Atlantic Ocean off the coast of Georgia, and he was never found again," Grant tells.
He was two-and-a-half years old at the time. His memories are of a few fun moments with his father, like when Dad would toss him in the shower and spray cold water on him.
"I loved it," Grant remembered. "He would get in there and we'd go crazy. Then, I'd go running through the house and hide." Grant's smile is unmistakable.
He doesn't remember the night the news came of his father's accident. What he does recall is his third birthday, and Kelly not being there, feeling as if it had been an eternity since he'd had a dad. He would cry himself to sleep on many nights.
"It was just hard for me to understand why God would let that happen to my mom and myself," he said.
Following Kelly's death, Grant and his mother, Susan, would move to Katy to be closer to Susan's family. It was there that she would meet up with another prominent former cadet.
In his time as Corps commander, Kelly Castleberry got to know Preston Abbott very well. Kelly's senior year came as Preston was a sophomore and the Corps' sergeant major, a title at the time that all but inevitably paved the road to Corps commander status. Indeed, Preston would become Corps Commander two years later, and then, a Marine like Kelly.
Preston became Grant's father figure when he and his mother met up. Then, he became Grant's father, marrying Susan in 1990.
"It's just a cool thing that my dad now knew my real dad and has been able to raise me like he thought that my dad, Kelly, would have liked me to be raised," Grant said. "He's been awesome. He's been the best dad that I could ever imagine."
The family would make a couple moves, one to Dallas, another back to Katy, where Grant would finish his high school career at Cinco Ranch. For the son of a pair of Corps commanders, there was no question about his next step in life.
"I did the only thing I thought I should do and join the Corps," Grant said.
For all the experiences Preston must have had in his A&M career, Grant says the true cadet experience wasn't really relayed to him.
"He didn't really tell me about the details of what it's like to be in the Corps," Grant said. "I guess he just decided he was going to let me figure it out for myself."
Grant initially wanted to do two things at A&M: become Corps commander and play for the football team. It didn't take long to realize it would have to be one or the other.
Or something else.
"I was like, 'It'd be really cool to be a yell leader because I could be in the Corps, but also, I could have an impact with the football team,'" he recalled.
It's a decision, Grant believes, that his Corps commanding father is happy with.
"I think he's glad that I didn't follow in his steps directly because I don't think he wanted me to," Grant said. "I think...as a matter of fact, I know he wants me to be my own person."
Sports in general are a passion of Grant's, so being up close for basketball, soccer and volleyball hasn't hurt, either. But it's football that is king in Aggieland, and without question, a packed Kyle Field is an experience unlike any other.
Grant's energy is catalytic. Sprinting from side to side, up and down the field, waving his towel, screaming his yells, pumping his fists -- the passion of a head yell leader might only be matched by an Aggie ball carrier on the field.
But it is that yell leader's job to make sure that Aggie athlete hears 80,000-plus in as passionate a state as possible.
"When I'm down on the field," Grant said. "I think of getting the 12th Man so involved in the game that it helps our team come out with the 'W.'"
And wins come from determination, perserverence and pride, qualities of one cadet who has continued a legacy of two fathers.
"I hope he's proud of me," Grant says of Kelly. "My dad, Preston, has told me several times that my dad would be proud of me."