CTSK and Miyoshi myopathy: Treatment of pre‐osteoclasts with MM cell‐derived EVs induces the expression of osteoclast markers such as cathepsin K (CTSK), MMP‐9 and tartrate‐resistant acid phosphatase (TRAcP), causing their differentiation into giant multinuclear osteoclasts with a capacity to excavate resorption lacunae (Raimondi et al., 2015).