Fig 2: Representative histochemical and immunohistochemical staining. Heterogeneous staining pattern combinations were detected among 105 cervical squamous cell carcinomas. Patients A and B: moderately differentiated Stage 1 tumors, wild type PIK3CA; patients C (poorly differentiated) and D (moderately differentiated): Stage 1 tumor, mutated PIK3CA. Scale bar 50 µm. All images were originally photographed with a ×20 objective lens using an Olympus BX50 light microscope (Center Valley, PA, USA) equipped with a QImaging Retiga 2000R digital camera (Surrey, BC, Canada) (PIK3CA staining is included in Additional File 2: Figure S1).