At present, there are currently no unified criteria to evaluate the immune function of PC patients, the practical assessment is always a comprehensive consideration of the presence or absence of basic diseases, a history of using immunosuppressive drugs, the total count and classification of white blood cells, humoral immune parameters, serum CD4+ and CD8+ levels, etc [19–21, 28–29]. The gene discussed is CD4; the disease is pachyonychia congenita.