As we have observed that PPARγ levels were unchanged in SKBR-3 and that PLIN1 and PLIN2 mRNA levels were not modified consistently in the two ERBB2+ BC cells co-treated with CA and Tz, we conclude that the activation of an aberrant differentiation process, possibly activated by CA and Tz, is unlikely to have a major role in cell cycle arrest caused by CA and Tz in our experimental context. This evidence concerns the gene PLIN1 and breast cancer.