Patschan et al14 demonstrated an up-regulation of OX40 on T-cells of SLE patients, with more clustering in those with active nephritis, although their results did not show any correlation between serum creatinine and OX40 expression, and they found similar percentages of expression among the different classes of nephritis. The gene discussed is TNFRSF4; the disease is systemic lupus erythematosus.