CCND1 and prostate cancer: An important study based on prostate cancer cells has revealed that curcumin induced the expression of cyclin-dependent kinase (CDK) inhibitors p16, p21, and p27 and inhibited the expression of cyclin E and cyclin D1 and hyperphosphorylation of retinoblastoma (Rb) protein [30] and another study has shown that suppression of cyclin D1 by curcumin led to inhibition of CDK4-mediated phosphorylation of retinoblastoma protein [31].