PSMC1 and melanoma: Figure 6A showed the frequencies of MIDN, NR4A1, PSMC1, and EGR1 positive expression in liver cancer, pancreatic cancer, breast cancer, and melanoma, respectively (Figure 6A). We further analyzed the subcellular locations of MIDN, NR4A1, PSMC1, and EGR1 using the HPA database. Interestingly, all four of these genes were at least located in nucleoplasm (Figure 6B). After analyzing the cBioportal database, co-occurrence tendencies (mutation) were found between NR4A1 and PSMC1, between NR4A1 and EGR1, between MIDN and EGR1, and so on (Figure 6C,D).