BTK and cancer: It has been commonly agreed that the PI3K pathway is also closely related to normal physiological activities of somatic cells.49 Unlike drugs targeting the PI3K/ATK pathway in the clinic for cancer therapy, which have toxic side effects on normal somatic cells, the ESC microenvironment have a strong positive influence on normal cells.50, 51, 52, 53 Thus, a comprehensive understanding of the tumor‐suppressive effects of ESC microenvironment could become a powerful tool in future antitumor therapy.