Outfit.

John DiFronzo was a capo before he became boss, and his brother Peter took over that crew. There's a crew led by the Frank 'Tootsie' Caruso, their patriarch was Frank 'Skids' Caruso who was part of the 42 Gang. Skid's grandson (Tootsie's son) was charged with the vicious racial beating of a young black teenager where Bill Clinton got involved. He had nothing to do with it, though. I don't know their relation, but Tootsie's soldiers include Bruno and Leo Caruso who have some blood ties to labor unions and the Roti Family, a political clan that had mob ties way back in Capone's day. Pudgy Matassa is the reputed head of the old Cicero Crew, which held the power in The Outfit since a long succession of bosses would be capos from that crew. But there's not much on him and it appears his soldier Michael Sarno runs an operation almost big enough to rival him. Maybe he's just attracting more attention though, Pudgy Matassa has the largest crew currently.

Joseph Cullotta is a capo as well but I don't know anything about him. Maybe he's related to informant Frank Cullotta.