Stromal cells are target of neoadjuvant chemotherapy in vivo. (a) Representative H&E stained sections from corresponding breast cancer samples before (left panel) and after (right panel) chemotherapy. (b) Clinical response and pathological response of stromal cells (upper panel) and tumor cells (lower panel). Before chemotherapy and before surgery, the two longest perpendicular diameters of the tumor were measured either by MRT or sonography. The product of these diameters was used as a measure of tumor size. Partial clinical response (cPR) was defined as reduction of tumor size of more than 50%; tumors with a reduction of less than 50% or induction of size were defined as non responders (cNR). Tumors with pathological stroma response (characterized by a reduction from stromal grade 2 or 3 to grade 0 or 1; upper panel) and tumors characterized by pathological tumor cell response (tumors with regression grade 2, 3, or 4; lower panel) are displayed as black columns.