MMP9 and necrotizing enterocolitis: Among the GO categories, the CC items exhibited the highest protein ratio values concerning “extracellular region” and “extracellular matrix (ECM)” (Fig. 5B), represented by the increased protein levels of P14780 (MMP9), D3DSM4 (COL18A1), and A0A140VJI7 (ECM1), underscoring the importance of extracellular activities during short-term development of NEC (Fig. 5D).