We would like to raise awareness of readers to the following.
Parts of figure 1 in this paper were previously published under a Creative Commons Attribution Licence (CC BY 4.0) as parts of figures 1 and 2 in Peng M, Peng F, Zhang C, Wang3 Q, Li Z, HuH, Liu S, Xu B, Zhu W, Han Y, Lin Q. Preoperative prediction of Ki-67 labeling index by three-dimensional CT image parameters for differential diagnosis of ground-glass opacity (GGO). PLoS ONE 2015; 10: e0129206. https://doi.org/10.1371/journal.pone.0129206