FXYD3 and cancer: Next, we conducted immunohistochemistry assays to analyze the ratio of NRP1 and FXYD3 double-positive cells (ancestor-like CSC enriched) among the NRP1-positive population or the ratio of IGF1R and FXYD3 double-positive cells (ancestor-like CSC enriched) among the IGF1R-positive population in pre- and post-NAC cancer tissues derived from 5 TNBC patients with partial response to NAC (Supplemental Table 3).