ALB and focal segmental glomerulosclerosis: Signal with m/z 1831.61, identified as a fragment of serum albumin protein (ALB; Swiss-Prot accession No.: P02768; Homo sapiens; the amino acid sequence matched was 432–447) [12], showed a lower peak area in healthy subjects compared with FSGS patients, but no differences were found on comparing healthy subjects with MCD patients.