MST1R and cancer: Cancers, in general, appear to be highly addicted to growth factor signals that are reflected in not only the overexpression of the growth factors themselves but also the expression of key intracellular signaling molecules.[21–22] We, and others, have previously shown that the RTKs such as EGFR, c-Met and RON are overexpressed and are highly active in lung cancers and MPM.