In MDSCs, TLR2 activation with bacterial lipoproteins favors cancer growth by enhancing MDSC recruitment, survival, and accumulation to the tumor site in mouse lung cancer, fibrosarcoma, lymphoma, melanoma, and colorectal cancer models and is also correlated with bad prognosis in human colorectal cancer tissues (Maruyama et al., 2015; Shime et al., 2017; Hangai et al., 2021). Here, TLR2 is linked to lung cancer.