The mGluR1 and its downstream signaling pathway in PCs involving Gαq (Offermanns et al., 1997), phospholipase C β3 and β4 (PLCβ3, PLCβ4) (Kano et al., 1998; Rai et al., 2021), and protein kinase Cγ (PKCγ) (Kano et al., 1995) are crucial for the late phase of CF elimination. This evidence concerns the gene GRM1 and cystic fibrosis.