MMP1 and cancer: Here we have shown that PLP deficiency, induced by 4DP feeding, is able to transform benign RasV12 cancers in more aggressive forms capable of generating secondary tumors as demonstrated by (i) migration of GFP cells into the brain VNC, (ii) membrane basement degradation, (iii) accumulation of Mmp1, and (iv) presence of GFP cells into the hemolymph of RasV12 4DP-fed larvae.