RAG1 and infection: Moreover, an excellent model for understanding the role of lncRNAs in the immune response and their modulation after infections is the zebrafish mutant line rag1. V(D)J recombination, carried out by the combined endonuclease activity of recombination activating gene 1 (RAG1) and RAG2, assembles the vast diversity of immunoglobulins and T cell receptor (TCR) genes14.