Of note, a PD-L1/CD80 cis-heterodimerization has been reported on APCs, able to preserve the CD80 capacity to activate CD28, thereby supporting the sustained functionality of intra-tumor CD28+ T cells while repressing the inhibitory activity of PD-1 and CTLA-4 (Figure 1A) [161]. The gene discussed is CD28; the disease is neoplasm.