CFTR and cystic fibrosis: It was shown for CFTR-targeting cystic fibrosis molecular therapeutics that combination therapies are superior to approaches that build on single substances (Phuan et al., 2018; Southern et al., 2018; Veit et al., 2018), and thus our category definition considering subcellular compartmentation and the order of interaction will assist in selecting candidate therapeutics for that act on CFTR at several steps vital for CFTR gene expression, protein maturation, and activation.