PPP1R1B and neoplasm: A significant reduction in tumor volume, both in terms of total tumor volume (p = 0.023, Figure 5C) and the volume of the largest tumor per mouse (p = 0.021, Figure 5D), was observed in PyMT/Ppp1r1b-/- mice at 20 weeks, compared to PyMT/Ppp1r1b+/+ mice at the same time point.