BAIAP2L2, short for brain-specific angiogenesis inhibitor 1-associated protein like 2, is involved in multiple biological functions. It is crucial for the maintenance of mechanotransducing stereocilia in cochlear hair cells [2,5,7]. It also participates in various signaling pathways such as VEGF, apoptosis, Wnt/β-catenin, AKT/mTOR, which are related to cell proliferation, migration, invasion, and apoptosis in cancer cells [3,4,6]. Gene knockout (KO) mouse models have been valuable in studying its functions.

In KO mouse models, inactivation of Baiap2l2 causes degeneration of the mechanotransducing stereocilia in cochlear hair cells, leading to profound hearing loss [2,7]. However, in vestibular hair cells, Baiap2l2 inactivation does not affect stereocilia development or maintenance [5]. In cancer-related studies, knockdown of BAIAP2L2 in various cancer cell lines, including HCC, prostate cancer, osteosarcoma, and gastric cancer, inhibits cell proliferation, migration, and invasion, and in some cases, induces apoptosis [1,3,4,6].

In conclusion, BAIAP2L2 is essential for maintaining the structure and function of cochlear hair cell stereocilia. In the context of cancer, studies using KO or knockdown models have shown its potential role in promoting tumorigenesis and cancer cell malignancy. These findings highlight the importance of BAIAP2L2 in both normal physiological functions and disease conditions, especially in cancer development.