A recent study developed an LC-MS/MS quantification method based on cleavable stable isotopically labeled peptides to quantify levels of podocalyxin and podocin in urine in a cohort of FD patients [114], and showed that urinary levels of podocin may be a good diagnostic marker for untreated male patients with the classic phenotype, and were significantly associated with levels of urinary lyso-Gb3 in the total number of patients included in the study [115]. The gene discussed is NPHS2; the disease is Fabry disease.