SDC1 and Miyoshi myopathy: Moreover, CD138 surface expression has been shown to dynamically drive the switch between growth and spread of MM depending on nutrient conditions (124), to also act as a co-receptor for transmembrane activator and CAML interactor (TACI) and APRIL, promoting the APRIL/TACI-associated pathways that induce proliferation and survival of cancerous PCs (125), and few studies have addressed the role of CD138 in bone disease, one of the pathognomic hallmarks of MM pathogenesis (50, 126, 127).