Following the trend registered in our test cohort, we observed frequent downregulation of eight genes and recurrent overexpression of all PGE2 synthases (PTGES, PTGES2 and PTGES3, Tukey’s HSD test P < 0.0001) in CRC tumors (Fig. 1b, Table 2). The gene discussed is PTGES3; the disease is colorectal carcinoma.