They found in both the healthy and IPF human parenchyma up to eight mesenchymal populations, with consistent identification of lipofibroblasts, myofibroblasts, smooth muscle cells, pericytes, a population homologous to murine Ebf1+ fibroblasts, an intermediate fibroblast subtype and mesothelial cells (Figure 2). The gene discussed is EBF1; the disease is idiopathic pulmonary fibrosis.