While the concern is valid, and toxicity due to anti-PD-1 and anti-PD-L1 therapies is a known issue [32], systemic therapy with PD-1 and PD-L1 blockers has been approved by the U.S. Food and Drug Administration (FDA) for a variety of cancers [33], which the researchers felt mitigated the concern [31]. Here, PDCD1 is linked to cancer.