Whether we call them Mesenchymal Stem Cells, Mesenchymal Stromal Cells, Multipotential Stromal Cells, Skeletal Stem Cells, or another name, this class of multipotent progenitor cells has been continuously studied for more than 20 years. After more than 20,000 papers on MSCs, it is important that the field establish benchmarks and consensus procedures that can lead to effective therapies. Importantly, the first autologous in vitro cultured MSCs were injected into recipients over two decades ago. Today, over 300 clinical trials have been initiated with MSC or MSC-like cellular therapeutics and clinical results continue to accumulate. However, there are questions related to many aspects of MSC science and clinical therapy that need further clarification and confirmation. For this special issue of Stem Cells International, we invite investigators to submit original research articles related to MSC science and therapeutics that will further stimulate the scientific community effort to understand and utilize these multipotential cells. We are particularly interested in new approaches with sound scientific basis that elucidate basic MSC processes, and MSC therapies that have a clear benefit or provide therapeutic improvement. Focused, concise reviews will be considered but authors should write to the editors before submitting.

Potential topics include, but are not limited to:

• miRNAs as MSC regulators
• Therapies where none existed before: but much promise
• Taking MSCs from the dish to the body
• MSC and interactions
• Improving MSC survival once delivered
• Use of MSCs in bone repair: forgotten or common practice
• Where have all the MSCs gone? Can vanishingly small numbers of MSCs provide lasting clinical benefit?
• MSC : stem cell fault or feature
• Does anyone really have a better MSC and how do we evaluate the claim?