The calculated mean Ki67 indexes were as follows—SCLC-A: 85.63% (SD = 13.43%); SCLC-N: 87.5% (SD = 12.58%); SCLC-P: 85% (SD = 5.77%); and SCLC-I: 81.67% (SD = 7.52%). Here, MKI67 is linked to small cell lung carcinoma.