STAT1 and neoplasm: We show that an elevated STAT1 transcriptional response is associated with a robust increase in GZMB (13-fold), CD8A (4.3-fold) and PD-L1 (2.6-fold) expression levels in STAT3Low tumours but not in STAT3High tumours (1.9-fold, 1.4-fold and 1.1-fold, respectively) (Fig. 6e).