COL1A1 and cancer: In cancer zone A, cancer cells primarily communicated through the COLLAGEN pathway via ligand–receptor interactions, including Col1a1-(Itga9+Itgb1), Col1a1-Cd44, Col1a2-(Itga9+Itgb1), and Col1a2-Cd44, with Col1a2-(Itga9+Itgb1)/Cd44 showing the strongest interaction strength (Figure S2B).