HHLA2 and pachyonychia congenita: For example, systemic immune inflammation index was defined as an independent risk factor for cancer specific survival and recurrence in resectable PC patients [5]; the infiltration levels of several lymphocyte phenotypes in microenvironment were closely related to the long-term oncological prognosis of patients with PC [6]; the abnormal expression of various tumor genes could predict the postoperative survival of PC (such as TRIM2, ALKBH5, and HHLA2) [7–9].