Fig. 2.

(a, b)Title: Intra-tumoural heterogeneity of PD-L1 expression; primary tumour. Description: Two sections of a primary NSCLC immunolabelled for PD-L1 (SP263). Fig. 2a demonstrates small scale heterogeneity. Fig. 2b demonstrates large scale heterogeneity. The red arrows highlight tumour cells strongly positive for PD-L1, the yellow arrows highlight tumour cells showing no expression.

NSCLC, non-small cell lung cancer; PD-L1, programmed death ligand 1. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).