Osbp2, also known as HLM, is a member of the oxysterol-binding protein (OSBP) family. It binds specifically to oxysterols, like 7-ketocholesterol, and is involved in processes such as lipid trafficking and metabolism [4]. It has been detected mainly in retina, testis, and fetal liver, and is associated with membranes [4].

In various diseases, Osbp2 shows significant associations. In hepatocellular carcinoma (HCC), it is related to prognosis, immunotherapy, and chemotherapy resistance. A Cox model including Osbp2 suggested unfavorable overall survival in the high-risk score group, and Osbp2 could inhibit NK and TIL cell infiltration, impair IFN responses, and contribute to chemotherapy resistance [1]. In pancreatic ductal adenocarcinoma (PDAC), overexpression of Osbp2 promoted cell migration, invasion, proliferation, and chemotherapy resistance, and decreased apoptosis through epithelial-mesenchymal transition [3]. In chronic myeloid leukemia, it was expressed in 80% of analyzed patients, potentially involved in maintaining the undifferentiated state for leukemogenesis [2]. It may also play roles in age-related macular degeneration, opisthorchiasis-associated cholangiocarcinoma, and is related to susceptibility and resistance of Pekin ducks to DHAV-3, as well as in the reproduction of Kashmir cattle [5,6,7,8]. In primary immune thrombocytopenia (ITP), its expression was lower compared to normal subjects, and it was negatively correlated with macrophage M1 polarization [9]. In bovine testes, the target gene Osbp2 was associated with sexual maturation [10].

In conclusion, Osbp2 has diverse functions related to lipid-associated processes and is significantly involved in multiple disease conditions including HCC, PDAC, leukemia, and ITP. Its role in these diseases provides potential directions for further research on disease mechanisms and therapeutic strategies.