PGP and neoplasm: As next steps, we plan to (1) confirm the functional role and activity of Pgp in the fibroblast secretome-mediated drug resistance in pNF1 monocultures vs. parallel cocultures with fibroblasts; (2) investigate the mechanism by which the fibroblast-derived secretome regulates Pgp expression, either through extracellular vesicle-mediated transfer or via secretome-induced expression; and (3) assess drug resistance following Pgp knockdown in pNF1 tumor cells.