It is noteworthy that proteins previously described to be hyperphosphorylated in DM1 were either not detected in DMSXL astrocytes by mass-spectrometry analysis (e.g., CELF1, CELF2, and MAPT), or did not show signs of altered phosphosites (e.g., GSK3B). This evidence concerns the gene GSK3B and myotonic dystrophy type 1.