PTGS2 and malignant colon neoplasm: Werecently reported that the combination of 9-cis RA and ciglitazone causes asynergistic inhibition in the growth of human colon cancer Caco2 cells, whichexpress high levels of p-RXRαprotein, and this is associated with the induction of apoptosis and inhibitionin the expression of both COX-2 and c-Jun proteins and mRNAs.