SIX1 and neoplasm: Finally, while our study focussed on the role of Six1 and Eya1 during sensory development, cell proliferation, morphogenesis and cytodifferentiation are also known to be affected in human patients in which Six1 and Eya1 are dysregulated, leading to sensory deficits after Six1 or Eya1 loss of function mutations (Kochhar et al., 2007) or enhanced tumour progression after Six1 or Eya1 up-regulation (Blevins et al., 2015; Liu et al., 2016).