Fig. 2From: Best practices in DNA methylation: lessons from inflammatory bowel disease, psoriasis and ankylosing spondylitisSample size requirements for genome-wide significance. Estimated sample sizes, expressed as the number of pairs, either twin pair or case-control, required to reach 80% power in twin and case/control designs using a genome-wide significance threshold of 1 × 10−6. Data taken from Tsai and Bell 2015Back to article page