Genetic studies have shown that microtia is linked to mutations in ROBO1/ROBO2, HOXA2, SIX1/SIX5, TBX1, or CHUK in humans (Cox et al., 2014; Huang et al., 2023; Lu et al., 2020; Quiat et al., 2022). Here, ROBO1 is linked to microtia.