CBL and cancer: While relatively little is known about how cancer cells evade the pro-apoptotic effects of μM TMX, there appears to be enough clues to offer a speculative hypothesis as follows: It was recently reported that overexpression of the c-Cbl ubiquitin ligase enhanced the ability of μM TMX to induce apoptosis in oestrogen receptor-α (ERα) positive (and TMX-sensitive) MCF-7 luminal epithelial cancer cells, while expression of the dominant-negative (70Z) mutant of c-Cbl (DN(70Z)-c-Cbl) inhibited such effects (Yan et al, 2011).