MKI67 and small cell lung carcinoma: The results of the present study revealed that the expression levels of p‐ERK1/2, Ki‐67 and CD31 in SCLC tumours were significantly reduced following apatinib treatment, suggesting that apatinib may also inhibit SCLC tumour growth by inhibiting the expression of p‐ERK1/2, Ki‐67 and CD31.