Consistent with this idea, the incidence of CIN in head and neck cancer patients treated with pantoprazole (PTZ), which is a PPI known to inhibit OCT2 (Nies et al., 2011; Hacker et al., 2015), is significantly lower in those without PTZ (Ghonaim et al., 2021). Here, SLC22A2 is linked to head and neck cancer.