We next tested the response of EML4-ALK or ALKATI expressing melanomas to ALK inhibitors in vivo. Xenograft tumors were generated from MB 2141 and MB 3429 cell lines and treated with crizotinib or ceritinib (Fig. 4A)...MB 2141 xenografts expressing the EML4-ALK fusions (and ALKATI) demonstrated a strong response to both inhibitors.