| abstract |
Disclosed are: an agent for reducing a cancer stem cell and/or a cancer progenitor cell, which comprises an inhibitor of a heat-shock protein-90 (Hsp90) family protein as an active ingredient; and others. The inhibitor of a Hsp90 family protein is a benzoyl compound represented by formula (I) [wherein n represents an integer of 1 to 5; R1 represents CONR7R8 (wherein R7 and R8 independently represent a hydrogen atom, a substituted or unsubstituted lower alkyl, or the like), or the like; R2 represents a substituted or unsubstituted aryl, or the like; R3 and R5 independently represent a hydrogen atom, a substituted or unsubstituted lower alkyl, or the like; R4 represents a hydrogen atom, or the like; and R6 represents a hydrogen atom, a halogen, a substituted or unsubstituted lower alkyl, or the like] or a pharmacologically acceptable salt thereof. |