This is particularly important in the context of MPS IVA because bone resorption proteins that form the osteoclast podosome require proteins such as F-actin-rich domain, protein 2/3 complex (Arp2/3), and myosin light chain to attach to the bone area for bone degradation (in the UNT group, we found several proteins elevated) (Arpc3, Arpc5, Arpc5l, Capza2, Myfpl, Myl2) [55,56]. The gene discussed is ARPC5; the disease is mucopolysaccharidosis type 4A.