Applying a cut off 5% VAF in the primary tumour FFPE DNA, targeted next-generation sequencing (NGS) identified 17 somatic missense mutations across 9 genes (CDH1, ERBB3, ESR1, GATA3, KMT2C, NF1, PIK3CA, MAP3K1, and TP53) in tumours from 13/16 patients. The gene discussed is PIK3CA; the disease is neoplasm.