CELF1 and myotonic dystrophy type 1: In the DM1 model line HeLa_CTG960_GFPMBNL1, very few P-bodies contained detectable levels of GFPMBNL1, while fewer P-bodies contained CUGBP1 compared to the control line, i.e. 40% of P-bodies contained CUGBP1 but only 3% contained both proteins (n=53 cells) (Fig. 4G).