COL1A1 and pancreatic ductal adenocarcinoma: Type I collagen (COL1A1 and COL1A2) was correlated with the resembling of TAMs in non-small cell lung carcinoma (NSCLC) while it was not correlated with the paucity of T-cell accumulation in pancreatic ductal adenocarcinoma (PDAC), which were consistent with our results [34,35].