Figure 1.

The proportion of viable mouse knockout strains that have one of three body weight outcomes relative to a comparison group: increased, decreased, or unchanged. The chart on the left illustrates data extracted from an on-line database (Mouse Genome Database) that describes the characteristics of mouse knockout strains, and the chart on the right summarizes a survey by e-mail of investigators who initially did not describe body weight of knockout strains but provided the information when queried.