NFKB1 and neoplasm: Previous IHC studies have shown NF-κB1 expression in normal colonic tissue47 as well as more frequent p50 nuclear staining in tumour tissue versus normal mucosa.22 Six blocks of tissue from our series that had been scored strong (n=3) or weak (n=3) for BCL-3 immunoreactivity were stained again for BCL-3 and NF-κB1 (examples shown in figure 1C).