A chemosensitivity assay showed that the most effective polypore mushroom extract was the methanol extract of T. versicolor (strain It-1), which inhibited the growth of 6 various solid tumors (A-549 and SWi573 [lung], HBL-100 and T-47D [breast], HeLa [cervix], and WiDr [colon]) at concentrations below 45 μg · mL-1, with a concentration as low as 0.7-3.6 μg · mL-1 causing 50% reduction in the proliferation of cancer cells in lung and cervix tumors.