For example, G protein-coupled receptor activity pathway, including important features (TAS2R20, CNR1, OR4K2, KISS1R, FFAR3, OR2B11, OR13D1, OR6Q1 and GPRC5C), is essential in neurodegenerative diseases such as AD and Parkinson’s disease (Wong et al., 2023; Schöneberg et al., 2004; Guimaraes et al., 2021). Here, OR4K2 is linked to neurodegenerative disease.