Table 1.

Categorization of gene knockout effects on body weight in mouse strains

Category	KO strains (N)
Nonviable	542
No BW info	1078
BW same	234
BW reduced	112
BW increased	11
N total strains	1,977

KO = knockout; BW = body weight. Same = body weight the same as an appropriate control group, e.g., littermates. For a description of strains selected for study and the definition of "nonviable," see the text.