Fig. 2.

The redox ratios (a), NADH fluorescence (b), and FAD fluorescence (c) of the HER2-overexpressing cell lines (SKBr3 and BT474) changed significantly following trastuzumab treatment ($p<0.001$). Conversely, the HER2-negative cell lines (MDA-MB-231 and MCF7) showed no significant changes in redox ratio nor in either of its components (*$p>0.05$ compared with control) with trastuzumab treatment. These trends match published results using multiphoton microscopy.¹³