Prof. Paul J. Simmons was Head of Research & Product Development at Mesoblast Ltd., a cellular medicine company based in Melbourne, Australia founded in part on patents covering his pioneering work on the isolation of mesenchymal stromal cells (MSC). He currently acts as Chief Scientific Advisor to the company. His move to Mesoblast in 2011 followed a long and distinguished career in stem cell research spanning nearly 30 years. Ph.D studies at the Paterson Institute, Manchester UK under Prof TM Dexter FRS fostered a career-long interest in hematopoiesis and bone marrow stromal cell biology. Postdoctoral training at the Terry Fox Laboratory, BC Cancer Research Centre, Vancouver, BC, Canada and subsequently (1986-1990) in the Department of Transplantation Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA headed by Nobel Laureate E Donnal Thomas led to his interest in the field of bone marrow transplantation and an appreciation of both of the importance and of the considerable challenges associated with translational research necessary to develop, test and implement stem cell based therapies for the treatment of hematological malignancies. Dr. Simmons began his academic career as the inaugural R.L. Clifford Fellow in Experimental Haematology (1990-94) in the Division of Haematology, Hanson Centre for Cancer Research (HCCR), IMVS, Adelaide, Australia and was subsequently appointed a Member (Professorial equivalent) of the HCCR. In 1999 he was recruited to the Peter MacCallum Cancer Centre (Peter Mac) in Melbourne, Australia as Program Head in Stem Cell Biology. In 2002, he was part of the team of investigators headed by Dr Alan Trounson who successfully competed for the Biotechnology Centre of Excellence funding that led to the establishment of the Australian Stem Cell Centre (ASCC) and from 2003 until December 2006, Dr Simmons was Director of the ASCC Adult Stem Cell Platform. Immediately prior to joining Mesoblast, he was Director of the Centre for Stem Cell Research at the Brown Foundation Institute of Molecular Medicine (IMM), University of Texas Health Science Center at Houston and held the C. Harold and Lorine G. Wallace Distinguished University Chair. As noted above, the major focus of Dr Simmons’ research has been to utilize the paradigm of the hematopoietic system as a model to explore the mechanisms that contribute to the extrinsic regulation of stem cells in adult tissues by their immediate tissue microenvironment (stem cell niche). He has received international recognition for his pioneering contributions to basic hematopoiesis research and of precursor cells for the stromal system of the bone marrow. To date his published works have been cited more than 25,000 times (h-index 78) and he has received some 250 invitations to speak at conferences and workshops both nationally and internationally, including multiple keynote addresses. His significant research contributions were recognized by his Presidency of the International Society for Stem Cell Research (ISSCR) from 2006 to 2007. Dr. Simmons has served on the editorial boards of multiple journals in the field of stem cell biology including Cell Stem Cell, Blood, Stem Cells, Stem Cell Reports, Experimental Hematology, Cytotherapy and Stem Cell Research and has been a reviewer for Science, Nature and various of the Nature periodicals, PNAS, and Journal of Clinical Investigation, amongst others. He is committed to translating discoveries in the field of MSC biology into new clinical strategies and cellular therapies to improve outcomes for currently intractable diseases and disorders. With the recent approval by the FDA of the first MSC cellular therapy, Ryoncil, for the treatment of steroid-resistant acute GvHD, Dr Simmons fulfils his long-held desire to contribute to the development of this burgeoning new field of cellular medicines from concept to clinic through to commercialization.