CD274 and neoplasm: In a study assessing these six antibodies for the detection of PD-L1 expression with microarray immunofluorescent staining, concordance among four antibodies (SP142, E1L3N, 9A11, and SP263) revealed regression of tumor tissue cores (R2 =  0.42–0.91) and cell line cores (R2 =  0.83–0.97) [28].