For Antonio McKee and his son A.J., fighting has been a constant, a presence as real as a family member. As a youth, Antonio was a wrestler who struggled with his temper and would occasionally turn a match into a fight. As an adult, he turned professional, fighting at hotels and fairgrounds and any other place promoters would put up a cage. Two decades later, he’s still in the business. He runs a successful if underrated fight team, the BodyShop, in Lakewood, Calif., and these days, it’s his son that is his top protégé. In fact, many believe that A.