ERBB2 and breast carcinoma: However, whereas no significant differences across breast cancer molecular subtypes were reported for glutamine levels (p = 0.27, ANOVA), the GLU/glutamine ratio significantly varied across subtypes (p < 0.001, ANOVA) with the basal-like subtype mostly contributing to such differences (HER2-enriched versus basal, p = 0.01, luminal A versus basal p < 0.001, and luminal B versus basal p < 0.001, Tukey post hoc analysis).