It is commonly assumed that there are two pathways for BC development, which are the activation of genes that accelerate cancer growth (RAS, FOS, MYC, ERBB-2, CCND1, EGF, EGFR, BCL-2, BIRC5, VEGF, bFGF, COX-2) and suppression of the genes that slow down the proliferation of the cells (p53, p21, PTEN, ARF, CDKN2A, TRAIL, RB, BAX, FAS, GSN, TNF, ICAM-1, CCAM-1, CAR, CDH). Here, CDKN2A is linked to breast cancer.