The comparison of the unnatural amino acid napthylalanine NfsB mutant and wild type NfsB activity for the pro-drug CB1954 and menadione; investigating the effect of the poly histidine tag on wild type NfsB substrate reduction; and G protein coupled cytokines fMLP & LPA induced potentiation of PDGF receptor signaling; protein kinase C: a possible point of signal integration for PDGF \(\beta\) receptor recycling.