Table 2.

Low allelic frequency and low malignancy risk mutations on ThyroSeq v2 considered to be “ThyroSeq negative” by institution. MSKCC, Memorial Sloan-Kettering Cancer Center; MCC, Moffitt Cancer Center; CSMC, Cedars-Sinai Medical Center; MSHS, Mount Sinai Health System.

	MSKCC (n=7)	MCC (n=11)	CSMC (n=0)	MSHS (n=3)	Malignant n (%)
“Benign” mutations
NIS overexpression (n=1)	1				0
PTH expression (n=2)		1		1	0
Low allelic frequency mutations
EIF1AX (n=2)	1	1			0
PTEN (n=1)		1			0
RAS (n=11)	4	6		1	2(18)
TERT promoter (n=1)	1				0
TP53 indeterminate* (n=1)		1			0
TSHR (n=2)		1		1	0
Malignant, n (%)	1 (14)	1 (9)	0	0	2 (10)

^*Indeterminate due to poor quality sequencing, suspicious for low allelic fraction mutation.