PER2 and breast cancer: we found that the TIMELESS expression level was upregulated in most of the significantly altered datasets (77 of 84 datasets, 91.7%), especially in breast cancer and lung cancer, whereas the expression levels of RORA, PER1, PER2, and CRY2 were downregulated in most of the significantly altered datasets (63 of 73 datasets, 86.3%; 44 of 49 datasets, 89.8%; 44 of 48 datasets, 91.7%; 49 of 52 datasets, 94.2%).