HLA-G and neoplasm: Therefore, by evaluating the entire HLA-G gene in PTC patients together with HLA-G expression in tumor specimens and sHLA-G plasma detection, we uncovered important associations between the HLA-G gene, taken as gene segments and/or as extended haplotypes, and: (i) the susceptibility to PTC development, (ii) tumor morbidity, particularly metastatic or multifocal tumors and poor response to conventional therapy, (iii) the magnitude of HLA-G expression in tumor specimens, and (iv) the presence or absence of detectable sHLA-G in pre-thyroidectomy plasma.