Tmem120b is a transmembrane protein-encoding gene. It is expressed in various human tissues, especially malignant ones. It has been implicated in several important biological processes and pathways. For instance, it may be involved in adipogenesis as it was found among genes related to fat accumulation in skeletal muscle of aged male mice [2], and in adipocyte differentiation where its paralog TMEM120A and itself are induced during 3T3-L1 adipocyte differentiation [3]. It has also been associated with oocyte nuclear maturation in PCOS patients through a ceRNA network [4], and was part of a gene signature for overall survival prediction in osteosarcoma [5].

In breast cancer, overexpression of Tmem120b promoted breast cancer cell proliferation, invasion, and stemness. It bound to MYH9, stabilized it by preventing its degradation by CUL9, and activated the β1-integrin/FAK-TAZ-mTOR signaling axis, thus accelerating chemotherapy resistance [1].

In conclusion, Tmem120b plays crucial roles in adipogenesis, adipocyte differentiation, oocyte nuclear maturation, and has a significant impact on cancer-related processes such as breast cancer cell stemness and chemotherapy resistance. Functional studies, especially those related to its over-or under-expression in relevant models, have provided insights into its roles in these biological and disease-associated processes.