TOP2A and small cell lung carcinoma: In accordance with the Ki-67 expression levels, the TOP2A-Average protein expression significantly increased from TC to AC (Mann-Whitney-Test: U = −4.165, p < 0.001) and from AC to SCLC and LCNEC (Mann-Whitney-Test: U = −6.376, p < 0.001/U = −3.811, p < 0.001) (see Figure 3).