HLA-G and gastric cancer: The expression of HLA-G has been shown in cancer stem cells (CSCs) of certain types of leukemia [235] and renal cancer [236] and in lymph node metastases of thyroid cancer [162], gastric cancer metastases [237], metastases of ovarian cancer [141], malignant melanoma [165,166,205], colon cancer [157], and breast cancer [219,238].