PRPS1 and melanoma: In addition, Pearson correlation analysis indicated that the protein expression level of NDUFS3 was positively correlated with that of PRPS1 (Pearson correlation coefficient r = 0.31, P < 0.001) and negatively correlated with that of p-PRPS1(S180) in melanoma samples (Pearson correlation coefficient r = −0.42, p < 0.001) (Fig. 7D).