CD8A and inborn error of immunity: Remarkably, several of the interfacing genes have roles in APC-T-cell immunological synapses (cd8a, zap70, orai1 and perhaps the summer-biased classical mhcIIa locus [27, 36–38]) and mutations leading to loss of function in their mammalian orthologues cause primary immunodeficiencies [27, 36–38].