The histopathological study of proctectomy specimens post chemoradiotherapy may confirm the absence of atypical cells in the mucosa and submucosa, both of them replaced by fibrosis and persistence of residual tumor in the periphery at a muscular layer level itself or at extramural level, concluding the histopathological staging as ypT2 or ypT3. The gene discussed is RAB11B; the disease is neoplasm.