CD40LG and neoplasm: Univariate Cox proportional-hazards regression model showed that distant metastasis, unresectability, large tumor size, low Karnofsky performance status scale, high-serum CEA (>3 ng/mL) levels, and high-serum sCD40L (>35,000 ng/mL) levels were statistically significant poor prognostic factors for PDAC (Table 6).