Young adulthood BMI may mark developmental factors that lead to acquisition of both lean and fat mass in childhood and adolescence, which may influence later risk of cancer.8 In this context, adult height indicates developmental factors that lead to greater linear growth,36 37 while leg length is thought to mark the quality of the environment in early life.38 They might be also linked to cancer risk through similar mechanisms as young adulthood BMI, but these hypotheses were not fully supported by the CKB findings. Here, CKB is linked to cancer.