Figure 2: Example of wild-type PIK3CA detection from a CT-guided biopsy sample (Case 3).(a) Section from a CT-guided biopsy sample stained with hematoxylin and eosin. The bar shows a distance of 50 μm. (b) Closeup of the same section showing the presence of breast cancer cells (indicated by red arrows). (c) and (d) High-resolution melting shows the absence of mutations in either exon 9 (c) or exon 20 (d) Blue lines, T47D DNA; red lines, MCF7 DNA; green lines, sample DNA. Absence of mutations was confirmed by sequencing.