Pkn3, also known as Protein kinase N3, is an AGC-family member. It is a serine/threonine kinase [1,4]. Pkn3 is involved in multiple biological functions, such as being implicated in the phosphoinositide 3-kinase (PI3K) pathway, cytoskeletal arrangement, and cell adhesion [3,5]. It has been suggested to play a role in oncogenesis and bone metabolism [2,3,5]. Genetic models like knockout mice are valuable for studying Pkn3's functions.

In mouse models, Pkn3 knockout (KO) mice showed suppressed angiogenesis, as demonstrated by ex vivo aortic ring and in vivo corneal pocket assays. These KO mice also had impaired lung metastasis of melanoma cells, indicating Pkn3's critical role in angiogenesis and tumor metastasis [3]. In addition, Pkn3-deficient mice had greater trabecular bone mass due to decreased osteoclast bone-resorbing activity, suggesting its role in bone-resorbing regulation [2].

In conclusion, Pkn3 is crucial for angiogenesis, tumor metastasis, and osteoclast-mediated bone resorption. The study of Pkn3 KO mouse models has revealed its significance in cancer and bone-related diseases, providing potential therapeutic targets for treating breast cancer, osteoporosis, and bone destruction in inflammatory diseases [1,2,3].