HLA-G and cancer: Although HLA-G expression has been documented in several other cancer sites, i.e. cervical cancer [15,34-37], melanoma [49-51], breast [49,52-54], colorectal [55-57], gastric [57-60], esophageal [57,61,62], lung [57,63,64], and other cancers [49], the implications of HLA-G methylation on the expression of the protein have not been described.