The latter two points, (i) the relevance of CTSB in lung cancer, and (ii) the potential of fisetin in interacting with CTSB, highlight the significance of the results of the present study (Supplementary information, Figure 1a), suggesting the potential of fisetin as suitable treatment for lung cancer through targeting the CTSB expression level. The gene discussed is CTSB; the disease is lung carcinoma.