KSR1 and Rectal prolapse: As noted in S1 Table, more female Ksr1+/- mice (6/12) were sacrificed due to rectal prolapse (compared to 1/5 males), while the trend was reversed for Ksr1+/+ mice (1/13 females compared to 3/9 males); however, it should be stressed that our sample size is too small to draw definite conclusions based on gender.