As ritanserin inhibits both DGKα and serotonin receptors (Boroda et al., 2017; Franks et al., 2017; Mizutani et al., 2018), we wished to determine whether Dgk or serotonin receptors are the key target for ritanserin in Drosophila in reducing scrib−/RasV12 tumour size in cooperation with trametinib by analysing specific DGKα or serotonin receptor inhibitors. The gene discussed is DGKE; the disease is neoplasm.