In cancer expression databases the expression levels of thousands of genes can be continuously measured under particular experimental environments and conditions due to the important advancement of DNA microarray technology. This technology made it possible to understand life on the molecular level, and enables to generate large-scale gene expression data. It has also been applied in a wide range of applications such as cancer prediction, diagnosis and drug discovery which is a very important issue for cancer treatment(Tarek, Abd Elwahab et al. 2017). Some well-known expression databases is BioXpress and (Wan, Dingerdissen et al. 2015), miRCancer (Xie, Ding et al. 2013), while Gene Expression Database (GXD) (Smith, Hayamizu et al. 2019).