Of note, we observed numerous DTU genes involved in RNA splicing, with 10 genes (e.g. HNRNPC, SNRPD3, QKI, and LUC7L2) increased major transcript usage and 18 genes (e.g. SNRNP48, NCBP1, CELF2, RALY, and PABPC1) decreased major transcript usage in the COVID-19 patients (Figs 3C and S3). Here, SNRPD3 is linked to COVID-19.