Phenotype Allele Zygosity Sex Life Stage Procedure Parameter Phenotyping Center Source P Value Data increased freezing behavior C4b homozygote male Early adult Fear Conditioning Cue Baseline % Freezing Time MRC Harwell IMPC 3.1E-6 //www.mousephenotype.org/data/charts?accession=MGI:88228&allele_accession_id=MGI:6144264&zygosity=homozygote¶meter_stable_id=IMPC_FEA_015_001&pipeline_stable_id=HRWL_001&procedure_stable_id=IMPC_FEA_001¶meter_stable_id=IMPC_FEA_015_001&phenotyping_center=MRC Harwell decreased lean body mass C4b homozygote male Early adult Body Composition (DEXA lean/fat) Lean mass MRC Harwell IMPC 1.32E-5 //www.mousephenotype.org/data/charts?accession=MGI:88228&allele_accession_id=MGI:6144264&zygosity=homozygote¶meter_stable_id=IMPC_DXA_003_001&pipeline_stable_id=HRWL_001&procedure_stable_id=IMPC_DXA_001¶meter_stable_id=IMPC_DXA_003_001&phenotyping_center=MRC Harwell