SERPINE1 and malignant colon neoplasm: The presence of increased senescence has been associated with improved outcomes and chemotherapy responses in colon cancer.[27] An elevated senescence index, based on the expression of p-ERK, HP1γ and PAI-1, all markers linked to senescence, correlated with better treatment responses to chemotherapy for stage IV colorectal cancer and longer progression-free survival (median 12 months vs 6 months, p = 0.04).