Ultimately, we identified 11 key candidate genes (EVI5L, RNASE2, PARP10, TMEM131, TNFRSF1B, BSDC1, ACOT2, SAC3D1, SLA2, P4HB, and PHF1), and a nomogram to diagnose IPAH in MS patients showing high diagnostic value was also established. Here, P4HB is linked to myeloid sarcoma.