The major feature segregating them from non-PMC42 cancer lines is high levels of mRNAs encoding hallmark components of the BM, such as collagen (various collagens, including type IV, preferred by mammary epithelium [4]), fibronectin (FN1), and laminins (subunits α1, α4, β1, and γ1). The gene discussed is LAMB2; the disease is cancer.