SDC4 and neoplasm: Ligand‒receptor analysis revealed that azvudine predominantly regulated signal transduction from tumor CD4+ T cells to other immune cells through SPP1-(ITGAV + ITGB5) and SPP1-(ITGAV + ITGB1), as well as COL1A1-(ITGA9 + ITGB1), COL1A1-CD44, and COL1A1-SDC4 (Fig. 6e).