The Ki-67 label index marks aggressive behavior in pituitary tumors, and the high-CNV group (Ki-67 positive ≥3%: 10/16 vs. Ki-67 positive < 3%: 1/8; P value = 0.02, chi-square test) was associated with a higher Ki-67 label index (Figure 4E). This evidence concerns the gene MKI67 and pituitary tumor.