Amongst the DEGs for LRTIs, known approved drug targets (TClin) were identified including: KCND3, CACNA1E, GABRG2, CHRNA5, KCND1 and ADRB2 for severe COVID-19; GABRG2, KCND1, CA12, CACNA1A, IMPDH2 and PDE1B for RSV-LRTI; CACNA1E, GABRG2, KCNK3, CHRNA5 and CHRNB2 for PTB as shown in Supplementary Table S8. Here, PDE1B is linked to COVID-19.