TBX1 and neoplasm: Knowing that paracrine interaction between human cancer-associated fibroblasts (CAFs) and malignant cells promotes invasion of malignant cells at the tumor-stroma border [1], we seeded lung adenocarcinoma cells A549 on the surface of a dense gel composed of collagen I and Matrigel, which closely mimics the tumor-associated microenvironment, with or without human CAFs embedded in the gels.