GSTM1 and autoimmune lymphoproliferative syndrome: Since splenomegaly, increased DNTs, increased B12 serum level, reduced thymic output, and positive DAT were consistent with a diagnosis of the primary immune regulatory disorder (PIRD) autoimmune lymphoproliferative syndrome (ALPS), we started treating our patient with sirolimus (2 mg/mq/day) (11): her Hb values improved, reaching a plateau at 12–13 g/dl, DAT became negative, spleen volume progressively reduced to normal (8 cm of longitudinal diameter after 6 months of therapy), and DNTs decreased below 1%.