CTLA4 and autoimmune polyendocrinopathy: Other gene polymorphisms associated with APS are detected in the CTLA4 gene [19] encoding for the cytotoxic T lymphocyte-associated antigen-4, the vitamin D receptor (VDR) gene [20], the IL2ra gene encoding IL2Ra (CD25) [21], the TNFα (tumor necrosis factor alpha) gene [22,23], the FOXP3 (forkhead box P3) gene which controls Treg development and function [24] and the MHC class I chain-related gene A (MICA) [25,26].