PTGS2 and neoplasm: By comparing the expression levels of ALDH3A1 in patient specimens from both tumors with those of COX-2 and PD-L1, an oncogenic/inflammatory marker and an immune signal, we found that high ALDH3A1 expression was invariably associated with high expression of both COX-2 and PD-L1, in sharp contrast to the consistent downregulation of these markers observed in tumor specimens displaying low expression of the enzyme (Figure 8).