identified several EC subsets in patients with COVID-19 [35]. These subsets included lymphatic (PROX1, MMRN1, RELN, PKHD1L1, CCL21, SEMA3D), arterial (VEGFA, EFNB2, DKK2, FBLN5, SERPINE2, CLDN10), venous (HDAC9, CPE, IL1R1, ACKR1, PTGS1), capillary aerocytes (EDNRB, HPGD, CA4, PRKG1, TBX2, RCSD1, EXPH5, EDA, FOXP2, CHRM2), two capillary subtypes (CA4, RUNX1, PRKCB and FCN3, VWF, PTPRB, NOSTRIN), and a mixed population (CD14, FCN3, GPIHBP1, SOSTDC1). This evidence concerns the gene CA4 and COVID-19.