Even though COX-2 was not differentially expressed between normal and tumour macrophages in the RNA-seq reanalysis (data not shown), presence of COX-2 in CD68+ cells expressing iNOS or near these populations was observed when we further stained FFPE blocks of colorectal cancer (Fig. 2B), supporting the hypothesis of a relationship between NO and inflammatory pathways in tumours. The gene discussed is NOS2; the disease is neoplasm.