I was wondering if someone could help me figure out what La Cosa Nostra's role was in the drugs trade was or still is?

Back in the day they ran the heroin in the US but eventually got busted and South American gangs took over. What role did the LCN have in the drug business after the French Connection era? Did they supply other organized crime gangs or did some just distribute to other wiseguys who sold it on down the line to neighbourhood dealers until it hit the street. And lastly I hear from Jerry Capeci that most just sell drugs--i think he means by that, that they are street corner dealer. If anyone has any info please reply thanks