PER2 and neoplasm: Consequently, this study has established that augmenting the expression of mPer2 can effectively impede tumor cell growth and instigate apoptosis in lung cancer-afflicted mice tumor cells, through regulation of the mitochondrial signaling pathway by p53. Miki et al [187] found that within the suprachiasmatic nucleus (SCN), p53 binds to the Per2 promoter, preventing binding of the Per2 promoter and CLOCK/BMAL1, resulting in a suppression of Per2 expression.