To define and compare the interactomes of the RNA binding protein HNRNPC in poorly vs. efficiently metastatic breast adenocarcinoma cells, we carried out immunoprecipitation of endogenous HNRNPC from parental MDA-MB231 cells vs. its highly metastatic isogenic derivate, the MDA-MB231-LM2 cells. We used a non-specific MOUSE IgG IP from each line as control. Each IP was performed in triplicate, and analysed by LC-MS/MS, on a Thermo Q-Exactive-plus instrument.