Using co-cultures and mouse subcutaneous xenografts of GH3 somatomammotroph cells and fibroblasts derived either from invasive pituitary tumors, non-invasive pituitary tumors, or from the sphenoid sinus mucosa of patients bearing non-invasive pituitary tumors (fibroblasts considered as normal by the authors), Lv et al. found that the CAF-marker α-smooth muscle actin (α-SMA), as well as VEGF, showed higher expressions in tumor-associated fibroblasts derived from invasive pituitary tumors than in the ones derived from non-invasive pituitary tumors or normal fibroblasts. The gene discussed is ACTA1; the disease is neoplasm.