Use of CFTR modulators during part or all of the pregnancy resulted in two maternal complications that were deemed related to CFTR modulator therapy (one pulmonary exacerbation and one incident of acute myelocytic leukemia [AML] were attributed to lumacaftor-ivacaftor; there are no other reports in the literature of AML in association with CFTR modulator use). This evidence concerns the gene CFTR and acute myeloid leukemia.