Prior studies of combined EGFR and MEK inhibition with panitumumab + trametinib, respectively, suggest that this regimen is highly toxic, with toxicities being primarily dermatologic in nature (dermatitis acneiform).20,21 Current trials evaluating MEK inhibitors with broader inhibitors of upstream signaling, including drugs targeting SHP2 and SOS, are ongoing and will determine the safety and efficacy of these combinations. Here, XYLT2 is linked to acneiform dermatitis.