Figure 9. Demonstration of co-localization of C4d and SARS-CoV2 spike glycoprotein in theskin of Case 3. The skin biopsy was stained for C4d showing significant vascular localization(DAB stain). Using NUANCE software C4d is highlighted green while COVID-19 spike proteinshows a red staining pattern; a yellow signal is discernible indicative of co-localization of C4dand viral protein within the microvasculature.