Starting from "In the Marxian Workshops: Producing Subjects" of Sandro Mezzadra, in this paper I will survey some of the most important contemporary discussions about Karl Marx's social and political theory. In order to focalize on the main concepts of the neo-marxism, in the first part I will consider the influence of the Frankfurt School, of Althusser's researches and of the Italian workerism. In the second part, I will point out the concepts of «multiplication», «extraction» and «cooperation» as the main categories of Marxian research proposed by Mezzadra.