The proteins elevated in CRLM-SD, which include five proteins i.e. SRSF7, hnRNPA1, PTBP1, hnRNPL, and PHF5A linked to trans-regulatory factor splicing suggest the involvement in alternative RNA splicing as a biological process of liver metastasis in this CRC-LM subgroup (Table 2) (53, 55, 60, 67, 68, 69). This evidence concerns the gene PTBP1 and colorectal carcinoma.