TCF7L2 and breast cancer: Furthermore, CCAT2 has been shown to physically interact with TCF7L2, by which the expressions of MYC, miR-17-5p, and miR-20a are up-regulated, resulting in activation of the WNT signaling pathway [7, 8, 26].CCAT2 also appears to be involved in migration and chemoresistance in a SNP-independent fashion in breast cancer [14].