CCND1 and cancer: Wang et al. (2017a) found that the expression of CTHRC1 in ESCC promoted the migration, invasion and metastasis of tumor cells via the activation of MAPK/MEK/ERK/FRA-1 signaling. In other cancers, such as CRC and breast cancer, MAPK/MEK/ERK signaling was also highly activated with the upregulated of cyclin D1, and proliferation was enhanced (Ding et al., 2016; Zhao et al., 2016).