moreover, double immunofluorescence staining of tumor tissue (primary mammary gland) sections 4 months after intraductal injection with antibodies against the cytoskeletal protein keratin 18 (anti-CK18) and collagen I showed areas of in situ growth with microinvasion (Figure S1C), extensive invasion (Figure S1D), and targetoid growth in the connective tissue around mammary ducts (Figure S1E). The gene discussed is KRT18; the disease is neoplasm.