In addition, inhibition of SIRT1 with 17-allylamino-17-demethoxy-geldanamycin (17-AAG) induces Hsp90/Hsp70 hyperacetylation and decreases the formation of the Hsp90 multichaperone complex and subsequent downregulation of P-gp in P-gp-positive human lymphoblastic leukemia MDR cell lines (CEM/VLB55–8 and CEM/VLB100 MDR) [54]. This evidence concerns the gene PGP and acute lymphoblastic leukemia.