Effect of 13-MTD on the induction of apoptotic cell death in SKBR-3 cells. Cells were pre-cultured for 24 h and treated with the fatty acid samples for another 4 h, and apoptotic cells were measured by Anexin V staining. Number of Anexin V stained cells in approximately 100 cells was counted and expressed as percentages of apoptotic cells. Data are mean ± SE of 4 analyses. Data not sharing the same letter shows statistically significant difference at p < 0.05 by Tukey-Kramer test.