I dont think the mob hold much influence in new york prisons either, rykers island for instance is basically dominated by bloods, latin kings, netas and trinitarios, and unless there cliquing up with hispanics i doubt any mob guys are gonna be holding any weight in there unless theyve got a good drug connect. MS-13 is actually a mexican mafia affiliated gang and they are considered as part of the surenos so is 18th street. The 13 in their name signifies the letter m in the alphabet.