Analysis of the RNA sequences generated from the Pathobiology of Early Arthritis Cohort (PEAC) study http://www.peac-mrc.mds.qmul.ac.uk/ indicated that PDGFR-β and PDGF-BB positively correlate with the pericyte/activated fibroblast genes NG2/CSPG4, αSMA/ACTA2, and Thy-1/THY1. The gene discussed is CSPG4; the disease is arthritic joint disease.