CTSL and Hepatic failure: In the clinical context,as already discussed, CTSL is a usefulmarker for severe COVID-19, and an essentialenzyme in the SARS-CoV-2 infection pathway. A single study noted 42 different clinical enzymes that diagnosevarious disorders, including cancer, liver failures, heart attacks,and more. Many of these should be amenableto the assay format we report here.