RPN2 and colorectal carcinoma: We further investigated whether RPN2 expression level was associated with any clinicopathological variables in 64 CRC specimens, which were classified into 2 groups based on RPN2 IHC staining level: a positive RPN2 expression group (n=28,43.8%) and a negative RPN2 expression group (n=36,56.2%) (Supplementary Figure 1).