In our model with selected cancer cell lines (MCF-7, HeLa, KTC-1, PC-3, Myc-CaP and HT 1080) and proliferating endothelial cell cultures, nanomolar concentrations of 17AAG, NVP-AUY922, geldanamycin and radicicol yielded only a slight (20–30%) increase in the intracellular levels of Hsp27 and Hsp40 but no significant changes in the expression of Hsp110, Hsp90 and Hsp60 (data not shown). This evidence concerns the gene MYC and cancer.