VER-155008 is an adenosine-derived inhibitor of heat shock protein 70 (Hsp70; IC50 = 0.5 μM) that is selective over Hsp90. It targets the nucleotide-binding domain (NBD) of Hsp70 and similarly binds the NBDs of Hsp70 cognates Hsc70 (Ki = 10 μM) and glucose-regulated protein 78 (Grp78; KD = 80 nM). VER-155008 inhibits the proliferation of human breast and colon cancer cell lines, inducing apoptosis or caspase-independent cell death. It induces the proteasome-dependent degradation of Hsp90 client proteins and potentiates the apoptotic activity of Hsp90 inhibitors. VER-15508 also triggers paraptosis in anaplastic thyroid carcinoma cells.