CEACAM5 and colorectal carcinoma: Moreover, when treated with exogenous CEA, CEA−/lo cells exhibited a remarkable increased anoikis resistance during CEA treatment, while free CEA took slightly effect on CEA+ cells (Figure 5D and Supplementary Figure S4B–4D), suggesting that CEA molecule, secreted by CEA+ CRC cells, may protect CEA−/lo cells from anoikis thus contributes to metastasis.