Consistent with the role of TGFβ in cancer progression (Padua and Massagué, 2009; Massague, 2012), we show that LTBP3, a protein that regulates TGFβ secretion and bioavailability (Chen et al., 2002; Munger and Sheppard, 2011) promotes primary tumor invasion and metastasis. This evidence concerns the gene TGFB1 and cancer.