As shown in Additional file 1: Fig. S1, it can be found that the expression levels of FGF2 and SCG2 in CRC are significantly down-regulated, while the expression levels of POMC and TNFRSF19 are significantly up-regulated, which is consistent with the previous difference results. In addition, it can be seen from Additional file 2: Fig. S2 that all four genes showed worse prognosis after high expression. Here, SCG2 is linked to colorectal carcinoma.