Table 3.

Intrinsic subtypes distribution in HER2-low tumors according to ERBB2 mRNA levels.

Intrinsic subtype	ERBB2 high (T3-T2)		ERBB2 low (T1)		HER2-low		pa	pb	pc
	N	%	N	%	N	%
Luminal A	140	51.5	44	31.7	184	44.8	<0.001	<0.001	<0.001
Luminal B	95	34.9	22	15.8	117	28.5
HER2-enriched	17	6.3	5	3.6	22	5.4
Basal-like	8	2.9	62	44.6	70	17.0
Normal-like	12	4.4	6	4.3	18	4.4
Total	272	66.2	139	33.8	411	100.0

ERBB2 is italicized, as per standard gene ID formatting guidelines. T1: tertile one; T2: tertile two; T3: tertile 3.

^aReferred to the comparison between ERBB2 high vs. low.

^bReferred to ERBB2 high vs. the overall HER2-low population.

^cReferred to ERBB2 low vs. the overall HER2-low population.