ERBB2 and breast cancer: The supervised partial least squares discrimination analysis (PLS-DA) showed that HER2-positive BC patients had a spatial distribution significantly different from that of the CTR group (Figure 2a) The classification model had good reliability (R2 = 0.79, Q2 = 0.47) yielding 90.7% of sensitivity and 92.9% of specificity without any potential risk of over-fitting (Figure 2b).