MAPK8 and Miyoshi myopathy: Restoration of its expression inhibits malignant proliferation through a synergistic triple mechanism—inducing G2 phase cycle arrest to block mitotic progression, activating the MST1-JNK/c-Jun apoptotic pathway, and inhibiting the MEK/ERK and PI3K/mTOR/Akt survival signals, thereby significantly inhibiting MM cell proliferation [16].