Figure 6

Validation of detected PTEN copy number loss by immunohistochemistry. Staining of HNSCC samples for PTEN was negative in all cases in which deep sequencing revealed a homozygous deletion or mutation. Representative samples shown: Abundant PTEN expression in the tumor tissue of sample 'P26_pos' (A) and sample 'P70_neg' (B); Deep-sequencing: No CNA; Absence of PTEN protein in the tumor tissue of sample 'P60_pos' (C) and sample 'P13_pos' (D); Deep-sequencing: PTEN copy number loss.