Mice lacking wild-type <i>Hras</i> develop more ADM and PanIN lesions at early time points.

<p>(<b>A</b>) Representative H & E stained section (arrowhead: PanIN lesion), (<b>B</b>) quantification of % total normal acinar area remaining per field (at 4x magnification, 5 fields from 10 mice, bar: mean ± S.E.M.), (<b>C</b>) % of fields with all normal acinar tissue (from <b>B</b>), and (<b>D</b>) % of lobules with the indicated highest grade lesion (Nml: normal, ADM: acinar-to-ductal metaplasia, 1A: PanIN-1A, bar: mean ± S.E.M.) of pancreata isolated from <i>Hras</i>^<i>+/+</i> versus <i>Hras</i>^<i>-/-</i> KC mice at 8 weeks of age. (<b>E</b>) Representative H & E stained section of a pancreas from an 8-week old KC mouse (arrowhead: acinar-to-ductal metaplasia). (<b>F</b>) % of lobules with the indicated highest grade lesion (Nml: normal, ADM: acinar-to-ductal metaplasia, 1A: PanIN-1A bar: mean ± S.E.M.) of pancreata isolated from <i>Hras</i>^<i>+/+</i> versus <i>Hras</i>^<i>-/-</i> KC mice at 4 weeks of age. (<b>G</b>) Representative pancreatic section from a 4-week old <i>Hras</i>^<i>+/+</i> versus <i>Hras</i>^<i>-/-</i> KC mouse immunostained for cells (DAPI, blue) and markers of acinar (amylase, red) and ductal (CK-19, green) cells to highlight ADM lesions (co-staining, yellow). (<b>H</b>) Number of amylase⁺/CK-19⁺ positive (ADM) cells per field (at 4x magnification, (at 4x magnification, 5 fields from 10 mice) from pancreata isolated from <i>Hras</i>^<i>+/+</i> versus <i>Hras</i>^<i>-/-</i> KC mice at 4 weeks of age (bar: mean ± S.E.M.). *P<0.05. ***P<0.0001.