These investigators examined the effect of 22(R)-hydroxycholesterol (22-HC) on cyclooxygenase-2 (COX-2) expression and found that this oxysterol stabilized the level of COX-2 mRNA via a p38-mitogen activated protein kinase (MAPK)-dependent mechanism leading to COX-2 protein accumulation in a CCA cell line. The gene discussed is PTGS2; the disease is cholangiocarcinoma.