We found that MCU depletion partially rescued STING depletion‐induced cell growth inhibition in vitro (Figure 2M–O; Figure S3L–N, Supporting Information), which correlated with reduced mitochondrial ROS (Figure 2P), suggesting that mitochondrial ROS/calcium increases may partially explain observed cell growth inhibition in STING‐depleted tumor cells (Figure S3O, Supporting Information). Here, MCU is linked to neoplasm.