PER1 and neoplasm: In further analysis of human data, we found that, unlike TP53 mutations which are associated with the Low PER1 expression group, the High PER1 and High PER1 groups are associated with STK11 mutations, significantly lower expression of the gene that encodes PD-L1 (CD274), and significantly lower ESTIMATE scores (a measure of immune and stromal cell infiltration and tumor purity).