RET and non-small cell lung carcinoma: The missense S904F mutation occurs in the activation loop of the kinase domain, and is able to increase the autophosphorylation activity of RET kinase and confer resistance to vandetanib in vitro through an allosteric effect and has been also reported as a mechanism of acquired resistance in a patient with NSCLC harboring CCDC6-RET fusion after treatment with vandetanib [98].