 The process of bone formation, remodeling and healing involves a coordinated action of various cell types. In an era of intensive bone tissue engineering research, these cell models are more and more often applied due to limited availability of primary human osteoblast cells. While they are a helpful tool in developing novel therapies or biomaterials, concerns arise regarding their phenotypic state. This article was authored by E. M. Chakanska, M. J. Stoddart, R. G. Richards, and others.