Jag2, also known as jagged canonical Notch ligand 2, is a ligand of the Notch signaling pathway. The Notch pathway is crucial for cell-fate determination, proliferation, apoptosis, and maintaining tissue homeostasis in various organisms. Jag2-mediated Notch signaling plays a significant role in multiple biological processes and is implicated in numerous disease conditions [4].

In non-small cell lung cancer (NSCLC), deletion of Jag2 in cancer cells attenuated tumor growth and activated anti-tumor T cell responses, indicating its role in tumor immune evasion [1]. In intervertebral disc degeneration (IVDD), recombinant JAG2 induced Notch2 and related gene expression, promoting nucleus pulposus (NP) cell proliferation and inhibiting TNF-α-promoted NP cell apoptosis. Intradiscal injection of JAG2 alleviated IVDD in a rat model, suggesting its importance in IVDD-related low back pain [2]. In ovarian cancer, JAG2+ tumor-associated neutrophils (TANs) mediated the differentiation of effector regulatory T cells, hampering PD-1 blockade response. Targeting Notch signaling or JAG2 could enhance the efficacy of anti-PD-1 therapy [3].

In conclusion, Jag2, through the Notch signaling pathway, is involved in various biological processes and disease conditions. Gene-knockout or conditional-knockout mouse models and other loss-of-function experiments have revealed its roles in cancer, IVDD, and other diseases, providing potential therapeutic targets for these conditions.