TOP2B and neoplasm: Moreover, previous research has shown that there are differences in the type and content of TOP2, the target of DOX, in cells with or without proliferative capacity.29 We found that the day 30 hiPSC‐CMs mainly express TOP2A, the gene for TOP2α, similar to tumour cells, whereas day 60 hiPSC‐CMs predominantly express TOP2B, the gene for TOP2β, which is similar to the phenotype of adult cardiomyocytes; therefore, day 60 hiPSC‐CMs can more accurately mimic DOX‐induced cardiotoxicity in the pathophysiological process of DNA damage (Figure 6).