In multivariate analysis, unmethylated RASSF1A (P = 0.039, Figure 2A), renal transplant history (P < 0.001, Figure 2B), preoperative renal insufficiency (P = 0.002, Figure 2C), and lack of bladder recurrence before the development of contralateral UTUC (P = 0.007, Figure 2D) were found to be independent risk factors of contralateral UTUC recurrence after RNU. Here, RASSF1 is linked to Renal insufficiency.