Finally, AZD4320 (a BCL2/BCL-w/BCL-XL inhibitor) synergised with ERK1/2 pathway inhibitors to induce apoptosis more strongly than AZD5991 in CRC, a disease with common KRAS or BRAF mutations that is as yet poorly served by ERK1/2 pathway inhibition. Here, KRAS is linked to colorectal carcinoma.