Table 3. Heritability of CES1 and CES1P1 mRNA expression levels in adipose tissue.
| Variable | rMZ | rDZ | h2 |
| CES1 | 0.82 (n = 23 pairs) | 0.26 (n = 32 pairs) | ∼1 |
| CES1P1 | 0.78 (n = 14 pairs) | 0.36 (n = 24 pairs) | 0.84 |
The heritability was determined as: h2 = 2[rMZ−rDZ]. In this equation h2 is the heritability coefficient; rMZ and rDZ are intra-class correlations within monozygotic (MZ) and dizygotic (DZ) twins, respectively. Due to missing biopsies or technical issues we only determined CES1 and CES1P1 mRNA level in a subgroup of the twin subjects. CES1: carboxylesterase 1 gene; CES1P1: carboxylesterase 1 pseudogene 1.