However, the inconsistencies of other studies, which report increased FOXP3 expression in PTC patients, may be attributed to differences of FOXP3 isoforms expressed among different cell types, FOXP3 subcellular localization, the studied Treg and tumor cell types, the methods of analyses, the sizes of compared samples, the tumor location and stage to draw conclusions, while in the vast majority of studies of FOXP3 expression they have not been conducted in association with FOXP3 rs3761548 genotypic data [23,53,60,61,62,63,64,65,66]. The gene discussed is FOXP3; the disease is neoplasm.