VSIR and cancer: By analyzing the Cancer Genome Atlas (TCGA) database, we found that expression of VSIR (PD-1H) mRNA in AML is the highest among over 30 different human cancer types (Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/JCI164325S1) (TCGA Research Network, 2013.