MAPK1 and digestive system neoplasm: KT7595, a gliotoxin derivative, and the farnesyl transferase inhibitor manumycin derived from streptomyces can inhibit FPTase by inhibiting the farnesylation of the p21 and the activity of the p42MAPK/ERK2 in its downstream pathways, thus inducing apoptosis and inhibiting proliferation of gastrointestinal tumor cells.