ERBB2 and breast cancer: In addition to elevated free fatty acid levels, there was an accumulation of palmitoylcarnitine (p < 0.001, one-way ANOVA), stearoylcarnitine (C18) (p < 0.001, one-way ANOVA), and oleoylcarnitine (p = 0.001, one-way ANOVA) in luminal B, basal, and HER2-enriched breast cancer, suggesting the conjugation of long-chain fatty acids to carnitine for transport into the mitochondria and subsequent oxidation in such tumors.