Additional file 2: of Clinicopathological and prognostic significance of PD-L1 expression in colorectal cancer: a systematic review and meta-analysis ShenZefeng GuLihu MaoDanyi ChenManman JinRongjia 2019 Figure S1. Forest plots assessing the relationship between PD-L1 and clinicopathological characteristics: (a) gender; (b) grade; (c) lymphatic invasion; (d) microsatellite instability; (e) mucinous properties; (f) stage; (g) the involvement of regional lymph nodes; (h) tumor differentiation; (i) tumor location; (j) the situation of primary tumor; (k) vascular invasion. (PNG 220 kb)