The invention discloses an application of KMT2D in the preparation of antitumor drugs, and belongs to the technical field of biological medicines. A
protein structure of KMT2D is analyzed through a
bioinformatics means, two essentially disordered structures LCD1 and LCD2 of the KMT2D
protein are finally obtained through screening, and the influence of the two structures on the KMT2D function is researched by combining the
gene editing technology, the change (including mRNA and
protein levels) of a KMT2D enzymatic complex is further researched, and thereby a foundation is laid for the deep understanding of a mechanism of KMT2D promoting tumor.