PIK3CA and cancer: Overall our FFPE STS tissue analysis identified one cancer-associated mutation in 2 of the 5 cases analysed – one involving the tumour suppressor TP53 and one involving the oncogene PIK3CA. This incidence of TP53 and PIK3CA mutations is slightly higher than those previously reported in larger cohorts of STS patients (20% vs 17% and 20% vs 18% respectively [30]), although clearly this small difference is most likely a result of differences in the cohort sizes analysed (47 vs 11) and/or variation in the particular STS subtypes enrolled.