PIR and colorectal carcinoma: These validation experiments confirmed that the expression of piR-1245, but not piR-26,525, was higher in CRC tissues, that its expression levels demonstrated a 5.49-fold (P < 0.01) and a 7.0 fold (P < 0.01) increase in CRC vs. NM tissue expression in the two cohorts (Additional file 4: Figure S2).