BAIAP2L2, also known as brain-specific angiogenesis inhibitor 1-associated protein like 2, is involved in multiple biological processes. It is crucial for the maintenance of mechanotransducing stereocilia in cochlear hair cells, and is associated with cell migration-related pathways such as Wnt/β-catenin, AKT/mTOR in cancer cells [2,3,5]. It also plays a role in immunity, methylation, and cuprotosis in hepatocellular carcinoma (HCC) [1]. Genetic models, especially KO mouse models, are valuable for studying its functions.

In KO mouse models, inactivation of Baiap2l2 leads to degeneration of the mechanotransducing stereocilia in cochlear hair cells, resulting in profound hearing loss, indicating its essential role in inner-ear function [2,7]. In cancer research, down-regulation of BAIAP2L2 in osteosarcoma, prostate cancer, and gastric cancer cells suppresses cell proliferation, migration, and invasion, and induces apoptosis, often associated with inactivation of related signaling pathways [3,4,5]. In HCC, BAIAP2L2 is overexpressed and promotes cell migration, invasion, and affects prognosis [1,6].

In conclusion, BAIAP2L2 has essential functions in maintaining the structure and function of cochlear hair cells. In the context of cancer, it promotes the malignancy of various cancers through different signaling pathways. The study of Baiap2l2 KO mouse models has significantly contributed to understanding its role in inner-ear diseases and cancer development, providing potential targets for diagnosis and treatment in these disease areas.