BTN2A1 and cranioectodermal dysplasia: Although these results were promising, due to the BTN2A1 gene being part of the extended MHC region and its close proximity (~4 Mb) to the classical MHC region (6p21.3), we could not exclude the possibility that this significant association could be secondary to the risk-associated HLA genotypes of the CeD patients [54,55].