Telomere length in thyroid tumors and adjacent normal thyroid tissue. Insets: White arrows indicate red-colored telomeric DNA; red arrows, blue-colored centromeric DNA. A: PTC and adjacent normal thyroid. Original magnification, ×40. The case had 100% FL-hTERT transcript. The telomere length was 0, very short compared with the adjacent normal thyroid tissue. B: FA and adjacent normal thyroid. Original magnification, ×40. The case had 14% full-length, 18% α-deletion, and 68% β-deletion hTERT transcripts. The telomere length was 1, notably shorter than the adjacent normal thyroid tissue. C: Dot plots of semiquantitative FISH assessments of telomere lengths in thyroid tumors. Comparisons of means using Student's t-tests showing a significant difference are indicated with their respective P values. *P < 0.02, **P < 0.006, ***P < 0.005, ****P < 0.002, and *****P < 0.0001. Means and standard deviations are shown.