PTK2B and systemic lupus erythematosus: The ratio of p-PYK2/PYK2 was examined and no significant difference was found between SLE patients (0.88 ± 0.19 for inactive SLE and 0.86 ± 0.20 for active SLE), RA patients (0.85 ± 0.21) and healthy donors (0.83 ± 0.18).