Kamaru ain't the only member of the Usman family making noise in the MMA world ...
Meet Mohammed Usman -- Kamaru's younger brother -- who's set to compete in the PFL's $1 million heavyweight tournament ... and turns out, fighting talent runs in the family.
32-year-old Mohammed is 6'2", 265 pounds -- and previously played defensive end at the University of Arizona.
Now, he's focused on MMA -- he's 7-1 as a pro and currently on a 4-fight win streak.