SPP1 and lung carcinoma: Despite that SPP1 is a well-known mediator of metastasis and a target for cancer therapeutics (Zhao et al., 2018), our data expand our knowledge on SPP1 by suggesting that the high expression of SPP1 in lung cancer is mainly due to its reduced methylation, and that SPP1 can affect the metastasis of lung cancer cells as well as chemoresistance.