Shp1 fl/+;MMTV-Cre and MMTV-Cre display a lactation defect.

<p>Shp1 fl/+ (control), Shp1 fl/+;MMTV-Cre, and MMTV-Cre female mice were mated with wild type FVB male mouse. On the first day following parturition, the litter size was normalized to 6 pups/litter. Pups were weighted at lactation days 5, 8, and 10. The average weight of each litter is shown and bars indicate the standard deviation (SD). ** indicates P<0.001. The data shown is representative of at least two independent experiments.