In hematological malignancies, BMAL1 expression levels correlate inversely with MYC levels [76], the PER genes are downregulated in CLL [97], NPAS2 is up-regulated in AML patients [98], and the CRY genes show both up- and down-regulation in CLL and AML [99, 100]. Similar associations have been reported in other cancers, including head and neck [101], colorectal cancer [83, 102], liver cancer [103], and lung cancer [104, 105] to name but a few. This evidence concerns the gene PER1 and B-cell chronic lymphocytic leukemia.