SPP1 and non-small cell lung carcinoma: The current study furthermore supports findings of superior outcomes in NSCLC patients with low OPN levels before chemotherapy [26] and is in agreement with the findings of Dehing-Oberije et al. who reported OPN pre-treatment plasma levels not to be associated with OS in a multivariate prognostic model for inoperable NSCLC treated by combined chemoradiation or radiotherapy [29].