In late-stage prostate tumors of PB-MYC mice (n=8 mice, 44-49 weeks old), micro-invasive carcinoma (MIC) was seen with nests of atypical tumor cells (EpCAM+ and CK5−) infiltrating into the stroma and forming irregular contours (Fig. 2C,C′; Fig. S5B). The gene discussed is KRT5; the disease is neoplasm.