text_1: The RANK-RANK-Ligand (RANKL) pathway is involved in the development of Aire-expressing medullary thymic epithelial cells (mTECs).
text_2: Here we show that the cytokine RANK ligand (RANKL) was produced by positively selected thymocytes and regulated the cellularity of mTEC by interacting with RANK and osteoprotegerin.