In agreement with a particular significance of autophagy and Hsp90 inhibition, autophagy induction by the nonsteroidal anti-inflammatory drugs (NSAIDs), celecoxib and its COX-2-inactive derivative 2,5-dimethyl-celecoxib in CD44-high K562 cancer stem-like cells, sensitized these cells to Hsp90 inhibition with 17-AAG [41]. Here, CD44 is linked to cancer.