Genes in this pathway, AICDA, CDADC1, CDA and APOBEC3D, were regulated in opposite directions (only AICDA was statistically significantly downregulated in SLE and CDA up in COVID-19), while APOBEC3A and APOBEC3B were significantly upregulated in COVID-19, but not SLE. Here, APOBEC3D is linked to COVID-19.