Scientists have developed a new way to grow and endlessly expand the immune-cell precursors that produce macrophages, opening the door to a powerful new generation of cancer immunotherapies. Credit: Shutterstock Scientists at USC Stem Cell have developed a new method for creating a renewable and expandable supply of immune cell precursors that could help advance cancer immunotherapy and other treatments. Published in the journal Cell , the study focuses on granulocyte-monocyte progenitors (GMPs)