The presence of well-known mutations reported in genes that commonly occur in EAC, known as driver mutations like ARID1A, CDKN2A, KRAS, APC, SMAD4, and PI3KCA, and a high tumor mutation burden (TMB) level makes EAC a highly heterogeneous disease [85,86,87]. The gene discussed is CDKN2A; the disease is neoplasm.