A group 3 innate lymphoid cell that express ROR gamma t and IL-7R alpha in the absence of lineage markers (e.g. CD3, CD19, B220, CD11c, Gr-1), with the functional ability to interact with mesenchymal cells through lymphotoxin and tumor necrosis factor. Lymphoid tissue-inducer cells are key to the development of lymph nodes and Peyer’s patches. [ http://www.ncbi.nlm.nih.gov/pubmed/29454785 http://www.ncbi.nlm.nih.gov/pubmed/9354470 http://www.ncbi.nlm.nih.gov/pubmed/19029905 GOC:add http://www.ncbi.nlm.nih.gov/pubmed/21601793 http://www.ncbi.nlm.nih.gov/pubmed/27935637 ]