Research on human glomerular mesangial cells (MCs) is mainly performed in vitro on primary MCs. Commercially available MCs originate from different donors and thus, because of their origin, the outcome of the experiments could potentially be affected. We have compared two commercially available primary human MCs (HMCv1 and HMCv2) using proteomics. Baseline differences and differences after treatment with a known proliferation factor (PDGF-B) were investigated.