High trans-fat intake has in adults been associated with several cancer types. Whether exposure to trans-fat also is associated with childhood cancers are unknown. Our main goal for this study is to strengthen the scientific basis for understanding idiopathic haematopoietic neoplasms in children by investigating societal changes in trans-fat intake and incidences of haematopoietic neoplasms, and investigate neonatal blood levels of trans-fatty acids in children diagnosed with leukemia and matched controls. Our study is the first study to assess the association between trans-fat exposure during pregnancy and risk of haematopoietic neoplasms in children. EnTRANCE is coordinated at The Parker Institute by Principle Investigator professor Berit L Heitmann, PhD and Postdoc Ina Olmer Specht, PhD in collaboration with scientists at the International Agency of Research of Cancer (IARC) in Lyon, France.