Recently, it was shown that activated GAS-responsive CD1a-reactive T cells were enriched in patients with psoriasis and were predominantly of the type 17 subtype, with a proportion of these being responsive to lysophosphatidylcholine, which is a known permissive endogenous CD1a ligand.35 Experiments performed using TCR-transgenic T cells generated via homology-directed repair confirmed these GAS-specific CD1a-reactive T-cell responses to be TCR dependent. Here, CD1A is linked to psoriasis.