Heat maps illustrating significant differences in phenotype parameters between C57BL/6N and C57BL/6J male and female mice. Parameters were assessed from each of the four centers: Helmholtz Zentrum Munchen (HMGU), Institut Clinique Souris (ICS), MRC Harwell, and the Wellcome Trust Sanger Institute (WTSI). Parameter designations and parameter descriptions are from EMPReSSslim . Significance levels and the direction of the effect (red and green) are defined in the key. Significant differences for categorical data are illustrated in blue. (A, B) Phenotype parameters showing a significant difference between N and J in (A) three or more centers, and (B) in two centers but no evidence of trends in the other centers.