CDKN1A and breast cancer: Effect of crocin on N-Nitroso-N-Methyl urea-induced breast cancer may be related to its potential suppression of cyclin D1 and p21Cip1 overexpression both in mRNA and protein levels, and therefore suppression of tumor growth, and induction of cell cycle arrest in this type of breast cancer cells through a p53-dependent manner (74).