Table 2.

Serum Calcitonin Levels in Medullary Thyroid Carcinoma Patients without Mutation in RET Proto-Oncogene (WO Group) with the Median of (7.35 pg/ml) was Significantly Higher Than Those Patients with Mutation (W Group) with the Median of (3.07)

	RET negative	RET positive
Sample size	40	42
Lowest value	2.01	0.34
Highest value	22.1	22.1
Median	7.35	3.07
95% CI for the median	6.0000 to 10.0322	2.0100 to 7.5528
Interquartile range	4.9000 to 12.3000	1.5000 to 11.8000
Mann-Whitney test (independent samples)
Average rank of first group	50.125
Average rank of second group	33.2857
Mann-Whitney U	495
Test statistic Z (corrected for ties)	3.201
Two-tailed probability	P = 0.0014