PDCD1LG2 and brain neoplasm: We tested the hypothesis that constitutive expression of PD-L1 and PD-L2 in brain tumor cells is caused, at least partially, by transcriptional activity of cis-regulatory elements near transcription start sites (TSS) of CD274 and PDCD1LG2. To identify candidate elements, we examined the University of California Santa Cruz Genome Browser (UCSCGB).