CCNE1 and neoplasm: CRISPR/Cas9‐based C14MC activation had tumor‐suppressive effects and noticeably (i) inhibited growth, proliferation, migration, and invasion; (ii) promoted actin cytoskeletal remodeling; reduced the number and length of filopodia; induced G2/M arrest; and increased senescence without significant changes in apoptosis; and (iii) decreased the expression of c‐MYC, the active form of AKT and CCNE; decreased lactate production and glucose uptake; and increased reactive oxygen species (ROS), intracellular Ca2+, and lipid peroxidation.