Of the 57 patients with a clinical diagnosis of CMC, a total of 35 (61 %) had heterozygous mutations in STAT1 (Fig. 1, Table 1); 26 of these cases were familial, affecting 9 of 11 families (82 %), whereas 9 of 18 sporadic cases (50 %) had STAT1 mutations. This evidence concerns the gene STAT1 and chronic mucocutaneous candidiasis.