Single-cell transcriptional profiles of COVID-19 patients
Single-cell sequencing data of eight healthy lung tissues, three mild, and six severe lung lavage fluid from COVID-19 patients were downloaded from the GEO database with the accession number GSE145926 (17). The quality control, standardization, integration, dimensionality reduction, and unsupervised cell clustering of the samples were carried out using R package Seurat (v3.0.2). For each patient, the same standard for quality control was used: 1) each cell expressed 200-6,000 genes, and the number of expressed genes was greater than 1,000; 2) each gene was expressed in at least three cells; 3) The proportion of mitochondrial genes was less than 10%.