Intriguingly, homozygous Lztr1-deficient mice (Lztr1–/–) exhibit embryonic lethality, whereas heterozygous Lztr1-deficient mice (Lztr1+/–) exhibit mild or no specific phenotypes, including cardiac hypertrophy and facial appearance (10, 26). Here, LZTR1 is linked to cardiac hypertrophy.