Emerging data also suggest that in colon cancer, use of MEK inhibitors in conjunction with checkpoint blockade may increase the efficacy of immune directly therapies in microsatellite stable (MSS) RAS mutant colorectal cancer; this strategy could also conceivably apply to gastric cancers, many of which display RAS-MEK-ERK pathway activation through receptor tyrosine kinase amplification [35]. Here, NTRK1 is linked to gastric cancer.