Question: What former Mexican drug lord is the nephew of the former leader of the Gulf Cartel (Spanish: "Cártel del Golfo" ) and Los Zetas?
Sentence (from "2012 Nuevo Laredo massacres"): But authors like Ioan Grillo and Sylvia Longmire note that Mexico's drug war actually began at the end of Vicente Fox's administration in 2004, when the first major battle took place in Nuevo Laredo between the Sinaloa Cartel and Los Zetas, who at that time worked as the armed wing of the Gulf Cartel.
Relevant evidence: No