RIPK4 and skin squamous cell carcinoma: Multivariate Cox regression analysis indicated that RIPK4 expression, along with LN metastasis and histological grade, was significantly associated with OS (HR = 2.085 and P = 0.038 for RIPK4 expression; HR = 2.331 and P = 0.011 for LN metastasis; and HR = 2.199 and P = 0.040 for histological grade), and RIPK4 expression and LN metastasis were significantly associated with DFS (HR = 1.742 and P = 0.037 for RIPK4 expression; and HR = 1.987 and P = 0.010 for LN metastasis) in CSCC patients (Table 3).