KL and pancreatic ductal adenocarcinoma: Notably, they found Kla was more abundant in gastric tumors tissues than adjacent tissues and suggested that high levels of Kla are associated with poor prognosis in GC patients [34]. In addition, pancreatic ductal adenocarcinoma (PDAC), the most intractable and lethal tumors with a 5-year overall survival rate of about 9% [13], is also characterized with severe hypoxia and lactate accumulation.