As BI-78D3 was previously reported to have an encouraging microsome and plasma stability (half-life of approximately 54 min)37 and had been shown to inhibit tumor growth of OVK18 xenografts that possess a naturally occurring PIK3R1L370fs mutation (10 mg kg−1 BI-78D3 was administered intraperitoneally four times per week for 3 weeks)52, we decided to test whether it inhibits ERK signaling in vivo. Here, MAPK1 is linked to neoplasm.