By comparing CTD-IP patients (n = 28) with the normal control group (n = 23), we found that CD3+ CD56+ NKT-like cells were significantly increased in the peripheral blood of CTD-IP patients (Fig. 2a and d, 6.26 ± 2.74 % in CTD-IP vs. 3.65 ± 1.27 % in controls, P = 0.003). This evidence concerns the gene NCAM1 and incontinentia pigmenti.