CLDN14 and nephrolithiasis: Howles et al. (2019) demonstrated that rs12626330, an intronic variant in CLDN14, was associated with nephrolithiasis. In this study, rs12626330 showed suggestive association with nephrolithiasis, and rs12626330 was correlated with higher level of serum uric acid and lower level of serum CO2. It has been reported that serum CO2 level was negatively correlated with the risk of uric acid stone formation (Moreira et al., 2015).