DICER1 and cancer: Among the 25 individuals with a germline DICER1 pLOF variant, 4 of 25 (16%) had a history of malignant tumor, which is comparable (by 50 years of age) to the frequency of neoplasms in the largest registry- and clinic-based (phenotype-first) DICER1 studies published to date.19,31,32 However, the penetrance estimate in the current analysis is conservative and limited by the small number of observations and multiple causes of underascertainment.