This is similar to ERK5 activation by RTKs in melanoma when MEK1/2 or ERK1/2 signalling is inhibited; through IGF-1R in BRAFV600E driven melanoma resistant to the ERKi SCH772984 (Benito-Jardón et al., 2019) or through PDGRβ in NRASQ61L/K driven melanoma resistant to the MEKi trametinib (Adam et al., 2020) (see above and Figure 3). Here, IGF1R is linked to melanoma.