MDK and esophageal cancer: It has been shown in endometrial cancer [27], esophageal cancer [28], liver cancer [29], and ovarian cancer [30] that the MDK - NCL signaling pathway affects the tumor immune environment through a variety of mechanisms, including promotion of immunosuppression, reduction of anti-tumor activity of immune cells, promotion of immune escape of tumor cells, and remodeling of tumor microenvironmental cytokine network, which ultimately favors tumor growth and proliferation.