CD28 and non-small cell lung carcinoma: These results are consistent with the findings of Kamphorst et al., who reported that HLA-DR+ CD28+ PD-1+ CD8 T cells (that also express CD38 and Ki-67) proliferate in the peripheral blood of non-small cell lung cancer (NSCLC) patients following PD-1 therapy (see Figure 4 of that publication).42