Heterogeneity of PDGFRA amplification in BI05. (A) Copy number estimates based on smMIP probe data. PDGFRA amplification (labeled) occurs in regions A and B with no amplification in regions C, D or E. (B) Results from Taqman qPCR targeting both PDGFRA and EGFR performed in quadruplicate. PDGFRA amplification occurs in regions A and B (between four- and eight-fold amplification) with no significant amplification in regions C, D and E. EGFR amplification occurs in all regions of BI05, consistent with MIP sequencing results. Heterogeneity of PDGFRA amplification was also confirmed through immunohistochemistry of regions A and E (Figure S9 in Additional file 1). Error bars represent the mean +/- one standard deviation from quadruplicate values.