PDCD1 and neoplasm: Preclinical evidence suggests that the combination of vascular endothelial growth factor/vascular endothelial growth factor receptor (VEGF/VEGFR) inhibitors and PD-1/PD-L1 inhibitors could lead to an increase in anti-tumor activity, by provoking T-cell function and modulating suppressive immune cells as well as the stroma, in the tumor microenvironment (Gunturi and McDermott 2014; Sharma and Allison 2015).