In marrow, PADI2 and PADI3 were elevated in some SARS-CoV-2 biopsies, and interestingly PADI2 was found to be elevated in marrow mesenchymal stem cells, which upregulates IL-6 via histone H3 deimination in multiple myeloma, contributing to chemo-resistance [132]. Here, PADI3 is linked to AL amyloidosis.