MBNL1 and myotonic dystrophy type 1: Consistently, knockdown of COX-1, but not of COX-2, upregulated MBNL1 expression in mouse C2C12 myoblasts/myotubes, human KD3 myoblasts/myotubes, mouse primary myoblasts, and myotubes differentiated from DM1 patient-derived iPSCs (Figs. 2 and 3).