Detection of HCMV expression by immunohistochemistry. Low-grade HCMV-IEA infection (A, B), low-grade HCMV-LA infection (C, D) and SMC-alpha actin (E) in tissue sections obtained from a GBM patient. Moderate to high-grade HCMV-IEA (F, G), moderate to high grade HCMV-LA (H, I) and SMC-alpha actin (J) in GBM. Bar, 50 μm Detection of HCMV DNA by in situ hybridization (K, L), Alu; positive control (M, P) and negative control (Q) in GBMs. Bar, 50 μm.