CCNA2 and cancer: Additionally, measurements of the genes BIRC5 and ASPA, BARD1 and PTPRB, CCNA2 and ACKR4 in lung cancer and normal lung tissue samples from datasets GSE18842 and GSE27262 were taken as an example to show that the qualitative transcriptional characteristics are robust in normal tissue samples (the expression value of ASPA (PTPRB, ACKR4) is higher compared with that of BIRC5 (BARD1, CCNA2)) but reversed in cancer tissues (Figure 2).