Table 1. Gene Expression Omnibus (GEO) datasets analyzed in this paper, ordered by increasing mean △log CV (see Fig. 2).

Dataset #	GEO name	Gene knocked out	RNA source	Repli-cates*	Reference	Use of litter-mates**
1	GSE22989	TGFBR2 (transforming growth factor β receptor, type II)	embryonic palate	5	[15]
2	GSE7676	Pcdh12 (protocadherin 12)	placenta	5	[16]	y
3	GSE31940	Pex5	gonadal adipose	4	unpublished
4	GSE41558	SRC-2 (steroid receptor coactivator-2)	heart	4	[17]	y
5	GSE12609	Arx (aristaless-related homeobox)	embryonic brain	4	[18]
6	GSE24683	Dicer	adipose	4	[19]
7	GSE47205	Mll (mixed lineage leukemia histone methyltransferase)	hematopoietic stem cells	5	[20]
8	GSE16381	Txnrd1 (thioredoxin reductase 1)	liver	4	[21]
9	GSE18326	FoxO3	forebrain neural stem cells	4	[22]
10	GSE27309	sirtuin 3	brown adipose	5	[23]	y
11	GSE17985	Dicer	oocytes	4	[24]
12	GSE8269	COX-1 (cycloxygenase 1)	gestational uterus	4	[25]
13	GSE13807	Dicer	embryonic mouse limbs	5	unpublished	y
14	GSE31958	Cryptochrome 1 & 2	embryonic fibroblasts	4	[26]
15	GSE8555	Phgdh (D-3-phosphoglycerate dehydrogenase)	embryonic head	4	[27]	y
16	GSE10895	MFP-2 (D-specific multifunctional protein 2)	liver	4	[28]	y
17	GSE15349	myostatin	muscle	5	[29]
18	GSE9123	PlagL2 (pleomorphic adenoma gene-like 2)	embryonic small intestine	4	[30]
19	GSE3843	Glycerol kinase	liver	4	[31]	y
20	GSE11899	Dicer	liver	5	[32]
21	GSE9012	Trim24 (TIF1alpha)	liver tumor	5	[33]	y
22	GSE7424	GalT (α1,3 galactosyltransferase)	transplanted heart	4	[34]
23	GSE27630	Otx2	choroid plexus	4	[35]
24	GSE38988	COX-2 (cycloxygenase 2)	pancreas	4	[36]
25	GSE7020	Nix	spleen	4	[37]

*Number of biological replicates

**“y” denotes datasets for which either the GEO annotation or the relevant publication included a specific statement that the knockout and wild-type mice compared were littermates (in the case of the other datasets, the use or not of littermates was not specified).