PDCD1 and neoplasm: Envafolimab (also known as KN 035 and ASC 22) is a first-in-class nanobody (single domain antibody) created by a fusion of the of anti-PD-L1 domain with Fc fragment of human IgG1 antibody that binds with high affinity and specificity to PD-L1, blocking interaction with PD-1, and resulting in T cell-mediated immune response to neoplasms.