AGRP and cystic fibrosis: This is in contrast to adults and juveniles of other CF populations such as Tinaja or Molino, who carry a mutation in the coding sequence of the melanocortin four receptor (mc4r) (Aspiras et al., 2015), a constitutively-activated receptor on which AgRP acts as an antagonist, including in fish (Cerdá-Reverter et al., 2011).