Sam Strober, MD, passed away at his home in California on Friday, February 11th. Sam was a friend to many of us and a giant in the field of allograft tolerance induction. He was a Professor of Medicine at Stanford University and remained dedicated to his professional goals until the time of his death from multiple myeloma. Sam devoted his career to the translation of his pioneering work in rodents using total lymphoid irradiation and anti-lymphocyte serum to achieve stable mixed chimerism without graft-vs-host disease into a protocol that can be applied to adult human organ transplant recipients. This clinical protocol was first applied successfully, with minimal GVHD, in patients with hematologic malignancies and later developed for the purpose of kidney allograft tolerance, with durable mixed chimerism and permanent graft survival off immunosuppression in HLA-identical donor-recipient pairs. He published hundreds of papers, received numerous honors and awards and will be sorely missed by his friends and colleagues in the transplantation community.