A recent specific retrospective study of 94 paired cases of lobular carcinoma demonstrated mutations in AKT1, ARID1A, ESR1, ERBB2, or NF1 only in 22% of patients with metastasis; PTEN and NF1 deletion and CYP19A1 amplification were seen in 19% of patients [66]. The gene discussed is NF1; the disease is breast lobular carcinoma.