Inhibitor that slows proliferation of secreting cells (also known as chalone). May function by binding to cell surface receptors. Requires cfaD for activity. Overexpression slows proliferation. Interacts with cfaD. Expressed at highest levels in vegetatively growing cells and declines during development (at protein level). Up-regulated by phagocytic stimuli. Cells proliferate more rapidly than wild type cells and exhibit supernumerary centrosomes and a cytokinesis defect. They also produce fewer spores at culmination. Belongs to the pqaA family.