text: Yo, check it out, let me break it down for you
  Insulin-like growth factor, known as IGF
  IGFBPs, they be influencing the action, see
  Since '88, eight forms of IGFBPs we know
  Different weights, amino acids, where they go
  
  They affect IGF activity, that's for sure
  Increasing the halflife when they on tour
  Potentiators of cell proliferation, alright
  Binding to surfaces, deliverin' with might
  
  Receptors get activated, cell responses too
  IGFBPs makin' moves, that's what they do
  Phosphorylation, glycosylation, proteolysis too
  Modifications affect their affinity, it's true
  
  IGFBPs ain't playin', they got another trick
  Actin' as inhibitors, blockin' IGFs quick
  No cellsurface bindin', activity on hold
  IGFBPs in control, keepin' it bold