However, repeated chemotherapeutic treatment stimulates the proliferation of tumor‐initiating cells (T‐ICs) in tumor residue, which have great capability of self‐renew and resistance to multiple drugs, leading to decreased chemotherapeutic effect and increased tumorigenesis.[85] To solve this problem, they developed an epigenetic therapy by loading lysine‐specific demethylase 1 (LSD1) inhibitor in the hydrogel to improve the chemosensitivity of drug‐resistant tumors, named as epigenetic hydrogel (epi‐gel). This evidence concerns the gene KDM1A and neoplasm.