LGR5 and neoplasm: The average DAB pixel density for the spontaneous tumor tissue was 10.5 ± 2.04 (mean ± SEM), γ-rays 6.7 ± 0.64 (mean ± SEM), and 56Fe 5.0 ± 0.98 (mean ± SEM), also indicating a decreasing trend in LGR5 expression after radiation exposure.