KRT19 and pachyonychia congenita: The level of cytokeratin-19 prior to treatment was independently associated with performance status (p = 0.0399) and disease stage (p = 0.0001) [179] Other proteins, such as the SLC16A3, SLC16A13, and S100 proteins, have also been identified as potential biomarkers for the prognosis of PC [180, 181].