If confirmed in a larger cohort, GH expression levels in tumor may serve as a biomarker for selecting patients for AS/OBI-821 vaccine therapy, similar to the use of programmed cell death 1 ligand 1 (PD-L1) expression for anti-programmed cell death protein 1 (PD-1) therapy.17 18. The gene discussed is PDCD1; the disease is neoplasm.