ALCAM and colorectal carcinoma: Subgroup analysis on the 5 studies that focused on overall survival based on testing methods, ethnicity, staining pattern and follow-up time revealed that high expression of ALCAM predicted poor prognosis of CRC patients in membrane and cytoplasmic staining (HR = 3.0, 95%CI = 1.92–4.69, P < 0.00001), IHC method (HR = 2.75, 95%CI = 1.70–4.44, P < 0.00001), Asian ethnicity (HR = 3.06, 95%CI = 1.65–5.69, P < 0.00001) and ≥ 50 (HR = 2.06, 95%CI = 1.22–3.48, P < 0.00001) groups (Supplementary Figure 7; Supplementary Table 1).