CDKN1A and plasma cell myeloma: Compound 1 induced the expression of the p53-induced cyclin-dependent kinase inhibitor Waf1/Cip1/Sdi1/CAP20/MDA-6/CDKN1A (p21Waf1/p21Cip1) [98], and downregulated the p53-suppressed cyclin D1 [109,110,111] protein factor in metastatic castration-resistant prostate cancer (mCRPC) cells, multiple myeloma U266 B lymphocyte lymphoblast cells and plasmacytoma RPMI-8226 B lymphocyte lymphoblast cells (data not shown).