Table 3.

HER2+ CSCs verus Non-HER2+ CSCs.

Parameter	HER2+ CSC	Non-HER2+ CSC
HER2 overexpression	Observed	Not observed
Subtypes	Lumial A, Luminal B and HER2+	All subtypes
Anti-HER2 agents	Effective for treatment	Not effective for treatment
Phenotype	High ALDH activity, mammosphere formation, invasiveness and tumorigenesis, as compared to Non-HER2+ CSC. Higher self-renewal and replicative potential.	Low ALDH activity, mammosphere formation, invasiveness and tumorigenesis, as compared to HER2+ CSC. Lower self-renewal and replicative potential, as compared to HER2+ CSC.
Genotype	Increased regulation of genes related to stem cells and progenitor cell control. Increased expression of genes related to S/G2/M transition. Reduced expression of genes involved in differentiation and immune response.	Decreased regulation of genes related to stem cells and progenitor cell control, decreased expression of genes related to S/G2/M transition. Increased expression of genes involved in differentiation and immune response, as compared to HER2+ CSC.