CD274 and ichthyosis prematurity syndrome: PD-L1 positivity was significantly associated with IPs (p < 0.001, n = 208; Fig. 7m), where ICs in both the IP1 (84.06%) and IP2 (89.47%) groups showed the highest positive rates, followed by IP3 (31.71%) and IP4 (31.82%), while ICs in the IP5 group had the lowest expression rate (2.86%) (Supplementary Table 3).