SLC5A2 and systemic lupus erythematosus: They proposed a threshold of 25% reduction in proteinuria as a marker of non-response [80] but without specifying whether this includes low-salt diet, a maximal tolerated dose of renin-angiotensin-system (RAS) inhibitors, and an inhibitor of sodium-glucose transporter-2 (SGLT2) or not, which all have substantial impact on proteinuria levels independent from the immunological SLE activity [70].