A survey including 1,077 patients did not show any increase in the cancer rate in PWS patients, except for acute myeloid leukemia (AML).39 It is one case where IGFBP7 could act as an oncogene,14 AML being associated with high IGFBP7 levels in bone marrow as a marker of severity.40 Therefore, the higher risk of AML in PWS patients could be due to high levels of IGFBP7, with GHT conferring protection by reducing circulating IGFBP7 levels. This evidence concerns the gene IGFBP7 and acute myeloid leukemia.