
Keywords: ADU, arbitrary densitometric unit; α2M, alpha-2-macroglobulin; IGF, insulin-like growth factor; IGFBP, IGF-binding protein; RGD, arginine–glycine–aspartate; RGE, arginine–glycine–glutamateAging; IGFBP-2; α-2-Macroglobulin; Fragmentation; Protein complexes