GSK3A and Miyoshi myopathy: Since GSK-3β Ser 9-phosphorylation is associated with a reduction in the enzymatic activity whereas GSK-3β Tyr 216-phosphorylation indicates activation [30], these findings, even if to be validated on a larger number of primary MM samples, indicate that the GSK-3β isoform may be less active than GSK-3α in normal PBMC and nPC as well as in MM cells.