MCAM and glioblastoma: To assess how pericytes regulate GBM cell response to TMZ, we co-cultured primary GBM cells (GBM-1 or GBM-2) and CD146+ pericytes isolated from human GBMs in the lower or upper chambers of transwells and added TMZ or dimethyl sulfoxide (DMSO) to the upper chamber (Fig. 3e).