SUMO2 and cancer: To identify inhibitors of the interaction of LANASIM and SUMO2, HEK293 cells were co-transfected with LANA WT-SmBiT and LgBiT-SUMO2, and then individually treated with 73 active compounds of natural products isolated from the Chinese traditional herbal medicines (which have been highly screened from thousands of compounds against cancer and deposited at SUTCM, supplemental S1 Table) at 50 μg/ml (a low-cytotoxicity concentration, and approximately 100 nmol/L(nM) based on molecular weight of selected single-molecule compound) concentration for 12 h, followed by luminescence assay.