ESR1 and cancer: At the moment, studies on human prostatic cells and prostate tissue from mice with obesity induced by high fat diet have shown that overweight and obesity promotes and androgenic to estrogenic switch in the prostate by overexpression of estrogen receptor α, which is widely accepted to mediate the negative effects of estrogens (inflammation, proliferation and survival of cancer cells), and by inducing SRD5A2 promoter hypermetilation and inhibiting SRD5A2 expression, resulting in lower 5-α reductase activity [45,46].