RAG2(Recombination activating 2) is a protein that is involved in the initiation of V(D)J recombination during B and T cell development. RAG2 plays a crucial role in the immune system by facilitating V(D)J recombination, a process essential for generating diverse antigen receptor genes in B and T lymphocytes. RAG2 protein, along with RAG1, forms a complex that introduces double-strand breaks in DNA, allowing for the rearrangement of immunoglobulin and T cell receptor genes from multiple germ line segments. RAG2 interaction with RAG1 is vital for initiating the recombination process, which ultimately leads to the production of a wide array of antibodies and T cell receptors necessary for effective immune responses.