There is a familial risk for hematologic malignan- cies, according to a study published in Cancers. Researchers investigated familial predisposition to hematologic malignancies using data from 316,397 individual twins participating in the Nordic Twin Study of Cancer with a median of 41 years of follow-up. The lifetime risk for any hematologic malignancy was 2.5%. However, this risk was elevated to 4.5% with a hematologic malignancy in a dizygotic co- twin and reached 7.6% if a monozygotic co- twin had a hematologic malignancy. Heritabili- ty of risk for developing any hematologic malig- nancy was 24% overall, which decreased across age. The estimated risk declined from approx- imately 55% at age 40 years to 20% to 25% after age 55, when risk stabi- lized. “In this largest ever studied twin co- hort with the longest follow-up, we found evidence of increased fam- ilial risk of hematologic malignancies and indi- cations of familial predisposition, not only within the hematologic malignancies but also between overall hematologic malignancy and other types of cancer,” the study authors wrote. “Heritable factors were most important among young and middle-aged adults.”