As a first approach to deciphering the cellular basis of MSMD and CMC in patients with inherited IL-23R deficiency, we compared the frequency of leukocyte subsets in the whole blood of healthy controls, five IL-23R-deficient patients, three IL-12Rβ1-deficient patients, and four patients heterozygous for STAT1 gain-of-function (GOF) variants (64), by CyTOF (Figure 3A and Figure S3A), and in peripheral blood mononuclear cells (PBMCs), by spectral flow cytometry (Figure S3B). Here, STAT1 is linked to hyperinsulinemic hypoglycemia, familial, 4.