BECN1 and breast cancer: Higher levels of autophagy have been observed in many types of cancer; e.g., the main autophagy regulatory gene Beclin1 is upregulated in colorectal cancer, gastric cancer, liver cancer, breast cancer, and cervical cancer, suggesting that autophagy may be involved in carcinogenesis and that Beclin1 plays a key role in tumor formation [19,20,21,22].