POLA2 was differential expressed between CRC tissues and peritumor tissues from multiple independent databases, including our own CRC tissues, Oncomine database (Gaedcke CRC tissues: GSE20842, Hong CRC tissues: GSE9348, Skrzypczak CRC tissues: GSE20916) and TCGA/GTEx CRC tissues. The expression data of POLA2 was calculated by applying log 2 (TPM+1) log-scale in a public dataset, and the expression levels of POLA2 were detected by qRT-PCR and normalized to that of GAPDH in our own CRC tissues. And P value was calculated by a two-sided Student’s t -test in TCGA/GTEx data, Hong CRC tissues, and Skrzypczak CRC tissues, whereas were calculated by a paired two-sided Student’s t -test in Gaedcke CRC tissues and our own CRC tissues.
