CD44 and neoplasm: Moreover, the treatment of C57BL/6 mice bearing dual B16 (parental tumor) and B16 radiotherapy‐resistant melanoma tumor with 30 Gy in two fractions to the resistant lesion resulted in a substantial increase in CD8+ T cells with effector phenotype (CD44+CD62L−) in the untreated parental tumor; however, the proportion of CD8+ T cells remained lower in the treatment‐resistant tumor.63