PGP and neoplasm: Several preclinical studies proved the efficacy of MBZ as an inhibitor of multiple processes accountable for tumor resistance and progression at nano- and micro-molar clinically reachable concentrations: unregulated angiogenesis [29,35,36,37], pro-survival pathways (such as SHH [39], XIAP [41], MAPK/ERK [43], and c-MYB [45]), protein kinases activation and expression (including VEGFR2 [35], BRAF [43,62], MEK [43], BCR–ABL [64]), matrix metalloproteinase 2 [32] and multi-drug resistance protein transporters P-gp and MRP1 [47].