Autoimmune cytopenia is seen in APDS, autoimmune lymphoproliferative syndrome (ALPS), CVID, SIgAD, STAT1 GOF, STAT3 GOF, DGS, immune dysregulation polyendocrinopathy enteropathy X‐linked (IPEX), CTLA‐4 haploinsufficiency and deficiency of LRBA, WAS, dominant‐negative defects in CARD11, ICOS deficiency, purine nucleoside phosphorylase (PNP) deficiency, and SCID (secondary to hypomorphic mutations such as RAG1 and ORAI1 mutations).6, 46. Here, ICOS is linked to immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome.