What was observed regarding NF-κB expression in the lamina propria of ileal and colonic biopsies in small cell GI lymphoma cats compared with IBD cats?

• A. Significantly increased in ileum only
• B. Significantly increased in both ileum and colon
• C. Significantly increased in colon only
• D. Decreased in both

Answer: (B)

NF-κB is a transcription factor that drives pro-survival and pro-inflammatory gene expression when activated by inflammatory or microbial signals. In the lamina propria of the GI mucosa, increased NF-κB activity reflects active inflammatory and neoplastic signaling. In cats with small cell GI lymphoma, NF-κB expression is significantly higher in both the ileum and the colon compared with cats with IBD, indicating widespread activation across multiple gut segments rather than a localized change. This broad upregulation aligns with how lymphoma-related microenvironments enhance inflammatory signaling and cell survival throughout the intestinal tract. The pattern would not be limited to one region or show decreased expression, which is why increased expression in both regions is the best description.