“…However, in the case of cartilage repair, which is a key target for regenerative medicine, several cell-based repair strategies already exist, including implantation of cultureexpanded articular chondrocytes, implantation of culture-expanded MSCs, and bone microfracture techniques, among other strategies (14,24,25). Admittedly, the desired outcome of cartilage repair has been inconsistent, and sometimes only modest results have been achieved, but investigators in the field recognize that factors other than the cells themselves, including growth factors, tissue scaffolds, the diseased microenvironment (26), and alignment of the joint (27), may have a crucial influence on the outcome (Table 2). Therefore, regardless of the source of the stem cell, these factors will have to be understood to maximize the benefits of stem cell therapy.…”