NLMB gang, after one of their members named Jamal 'Roc' Harris was murdered. Roc Block specifically refers to the area on 79th and Essex in Chicago, Illinois. Two well known rap artists associated with this particular block are Lil Bibby and Lil Herb whom explained what Roc Block is during an interview by saying “We from 79th and Essex “Roc Block” named after my brother Roc (RIP). That’s where we all grew up,” “The neighborhood really called Terror Town, but we roc block 79th and Essex N.L.M.B. Never Leave My Brothers.”
It's a very common tradition for gangs in Chicago to attach nickname to blocks in honor of their fallen members, for instance, JoJo World, O'Block, and Tookaville are all names adopted by gangs in honor of fallen members.