BMAL1–KD induced similar, and expected, gene expression changes in the two primary CRC cell lines: decreased NR1D1 and increased CLOCK expression, but without modification of PER2, CRY1 or CRY2. Reduced NR1D1 expression is consistent with the exclusive control of its promoter by CLOCK–BMAL1 binding to E-box regulatory elements [32] and the presence of two BMAL1 binding sites in the gene (Supplementary Figure 1) [33]. The gene discussed is PER2; the disease is colorectal carcinoma.