IGF1 and cystic fibrosis: The basis for weight reduction in Cftr(F508del/F508del) mice is not fully understood but is thought to be related to decreased food intake (although there is some controversy) (De Lisle and Borowitz, 2013; Rosenberg et al., 2006), reduced IGF-1 levels (Rosenberg et al., 2006), and/or changes in the tissue secondary to dehydrated and static mucus (De Lisle and Borowitz, 2013; Scholte et al., 2004; van Doorninck et al., 1995), hallmark features of Cystic Fibrosis.