SPP1 and lung cancer: Previously, the upregulation of SPP1 was found to be linked to gastric cancer (Junnila et al., 2010), osteosarcoma (Dalla-Torre et al., 2006), ovarian cancer (Zeng et al., 2018), oral squamous cell carcinoma (Huang et al., 2014), etc. SPP1 upregulation was also found to be linked to immune escape of lung cancer (Zhang et al., 2017).