The Regulatory Myeloid Cells -- International Immunopharmacology Conference in October 21-24, 2010 reviewed the recent advances in our understanding of the biological mechanisms of expansion, activation, metabolism and mechanisms of T-cell suppression of Myeloid Derived Suppressor Cells (MDSC). Lectures were focused on the control of the microenvironment and cytokines needed for myelopoiesis, interactions with the neoplastic surrounding cells for a negative immune control, and the role of MDSC in cancer promotion. The complexity of the tumor microenvironment and opportunities for therapeutic interventions by targeting, and/or manipulating MDSCs was emphasized. A better understanding of the crosstalk between myelo- and lymphoid arms of the immune system and of the metabolic alterations contributing to cancer phenotype provide new insights for the development of more efficient tumor immunotherapy strategies. This meeting report aims to provide the readers with a summary of the research highlights on human and mouse MDSCs presented in the meeting.