2‐PY is a major NAD+ metabolite that increases with age and illness (Slominska et al., 2004) and has been recognized as a uremic toxin in patients with kidney disease (Lenglet et al., 2016) that may exert toxic effects on the tissues (Rutkowski et al., 2003) and inhibit PARP‐1 activity (Slominska et al., 2006). Here, PARP1 is linked to kidney disorder.