We found that 76.6% of the MM tumor samples exhibited reduced GAS5 expression, compared to that in adjacent noncancerous tissues (P < 0.001), and a significantly greater number of patients with Breslow thickness > 4 cm, TNM stage > II, ulceration, and lymph node metastasis exhibited reduced levels of GAS5 in their MM tissues (P < 0.001 for all). This evidence concerns the gene GAS5 and Miyoshi myopathy.