Perforin and CD107a (lysosomal‐associated membrane protein‐1, LAMP‐1) were employed as two markers of NK cell functional activity.29, 30 To confirm the correlation between the impact of MCT4 inhibitor on tumor growth and the functional activity of NK cells, an evaluation of CD107a and perforin concentration was conducted by ELISA. Here, PRF1 is linked to neoplasm.