CHDH and nasopharyngeal carcinoma: Comparison of these published results with the current study, which looked at these biomarkers in a cohort of patients with LSD disorders, shows that the PPCS/lyso-SM ratio for NPC is more sensitive (92%) but less specific (63%) and that the GlcCer/CDH C24:2-OH ratio is slightly more discriminatory when looked at in an LSD cohort, with 96% sensitivity and 83% specificity.