HSP90AA1 and melanoma: In addition, both quantitative polymerase chain reaction (qPCR) and Western blot analysis revealed relatively higher expression of Hsp90 genes, particularly Hsp90aa1 and Hsp90b1, in the control tumor tissue (CTL) collected at ZT3 versus ZT15; however, this daily variation was not observed in Bmal1 KO melanoma tissue (Fig. 5, I and J, and fig.