Pten Cre-mediated editing in mice with mammary gland-specific loss of E-cadherin efficiently generates carcinoma-initiating cell that developed intraductal cell carcinoma while the infection with the Cas9 system stimulated an immune response that limited the success of Pten knockout inducing tumor that do not resemble the intraductal histotype [23]. The gene discussed is PTEN; the disease is infection.