The studies with the PTK inhibitors provide evidence that protein tyrosine phosphorylation is important in (i) modulation of nociceptive responses induced by peripheral k/c arthritis, (ii) induced NMDA NR1 subunit expression increases in the spinal cord, and (iii) NMDA NR1 subunit trafficking from the cell membrane to the nuclear membrane. The gene discussed is PTK2B; the disease is Arthritis.