We further investigated the signalling pathways involved in the development of polyps, and the results showed that the TNF‐α response via NF‐κB was uniformly upregulated in all cell subsets of both SJP and JPS polyps (except for epithelial cells) as well as some cell subsets (T/ILC cells, B cells, plasma cells, myeloid cells and fibroblasts) of PJS polyps but downregulated in epithelial cells in PJS polyps (Figure 2G). This evidence concerns the gene TNF and juvenile polyposis syndrome.