DDR1 and lung cancer: DDR1 expression has been associated with an increase in tumor invasion and aggressiveness of many human tumors, including esophageal cancer (Nemoto et al., 1997), gastric cancer (Xie et al., 2016), glioma (Yamanaka et al., 2006), breast cancer (Malaguarnera et al., 2015), and lung cancer (Xiao et al., 2015).