PU-WS13 is a selective Grp94 inhibitor (EC50 0.22 μM), slightly suppressing Hsp90α (27.3 μM), Hsp90β (41.8 μM), and Trap-1 (7.3 μM). It shows no toxicity to nonmalignant cells at 2.5-20 μM, disrupts HER2 circular architecture in SKBr3 cells, and induces apoptosis in HER2-overexpressing breast cancer cells.
