As seen that miR-638 was reversely regulated by both circ-PTK2 overexpression and knock-down, and miR-638 involved in MM-related pathways such as MEK&ERK and WNT&β-catenin signaling pathways, we further performed luciferase assay which validated the direct biding between circ-PTK2 and miR-638 in MM (Figures 5A, B). Here, MAP2K7 is linked to Miyoshi myopathy.