Wang et al. established a SMAD4/DPC4-driven immune signature (SDIS) in ICGC-AU2 (microarray data) through a machine learning algorithm, which was validated by database analysis, and multivariate Cox regression showed that SDIS can be a powerful predictor of prognosis in PC and can be used to further adjust chemotherapy and immunotherapy decisions in the clinical setting [83]. Here, SMAD4 is linked to pachyonychia congenita.