Additional file 3: of Clinicopathological and prognostic significance of PD-L1 expression in colorectal cancer: a systematic review and meta-analysis

Figure S2. Subgroup analysis of heterogeneity sources: (a) Asian; (b) non-Asian (c) stages I–IV; (d) follow-up more than 5 years; (e) follow-up less than 5 years (f) postoperative adjuvant chemotherapy; (g) sample size ≥ 200; (h) sample size < 200. (PNG 287 kb)