PTGS2 and digestive system neoplasm: Our rationale for utilizing celecoxib was that SERCA is a known non-COX-2 target of celecoxib and would therefore aggravate ERS, while at the same time celecoxib has been shown to inhibit MUC2 expression and decrease mucinous tumor growth in ex vivo and in vivo models of mucinous colon/appendix cancers [10, 13, 15].