FN1 and infection: MAM7 is a transmembrane protein that consists of a transmembrane motif at the N-terminus and seven mammalian cell entry domains that mediate its adherence to different types of cells by binding to fibronectin (Fn) and phosphatidic acid in the initial stage of infection and subsequent cytotoxicity against 3T3 fibroblasts and RAW264.7 macrophages, but not to HeLa or Caco-2 epithelial cells.