PDCD1 and disease arising from reactivation of latent virus: In line with our MIBI-TOF analysis, differential expression of genes associated with regulatory myeloid cells (e.g., PD-L1, PD-L2, CD11b, CD11c and CD163) or T cell immune checkpoint (e.g., PD-1 and CTLA4) delineated active from latent infections (Fig. 6d).