CHIA and neoplasm: RAP response to trametinib was strongly impacted by knockdown of blanks (human orthologue ADARB1), chitinase 4 (cht4, human orthologue AMCase or CHIA), major facilitator superfamily transporter 14 (mfs14, human orthologues SLC17A2, A3, A5, A7 and A8); chitinase 5 (cht5, human orthologue CHIA) weakly impacted trametinib response in RAP tumours (Figs. 3D,E; EV3B–E).