Coculturing of CAFs with prostate cancer PC-3 and DU 145 cells with the KLF5KR mutant released more Fgf9 than did the WT control at both the mRNA and protein levels (Figure 6, A and B), indicating that the signal from prostate cancer cells was essential for CAFs to release FGF9. The gene discussed is FGF9; the disease is prostate cancer.