By detecting circ_DOCK1 expression in 42 paired tumor and normal tissues, results showed circ_DOCK1 (hsa_circ_0020397) level was significantly increased in colorectal cancer tissues compared with normal samples (Fig. 1a), while hsa_circ_0020394 level was not obviously changed in tumor and normal samples (Supplementary Figure 1). This evidence concerns the gene DOCK1 and colorectal cancer.