Although several trans-synaptic adhesion molecules have been identified to contribute to CF-PC synapse maintenance or elimination including Sema3A-PlxnA4, Sema7A-PlxnC1/ItgB1, Sort1-progranulin, BDNF-TrkB, and C1q1-Bai3 (Uesaka et al., 2014, 2018; Kakegawa et al., 2015; Choo et al., 2017), specific synaptic molecules involved in the formation and/or maintenance of CF synapses during perinatal stages or synaptic molecules with differential functions in cerebellar lobules related to the Aldoc expression are yet to be identified. Here, BDNF is linked to cystic fibrosis.