We further analyze CRISPR/Cas9 screening sequencing data from mouse colorectal cancer liver metastasis models and compare differential genes (positive and negative) between control and experimental groups and surprisingly found differential genes associated with interleukin 2, interleukin 15, TGFb1, neutrophils, HIF1ɑ, inflammatory response, TAL1, and B lymphocytes (Fig. 1L-M), suggesting that liver metastasis of CRC might be closely related to tumor immunity. This evidence concerns the gene IL2 and colorectal cancer.