To determine the response of prostate cancer cell lines to pharmacologic ALK inhibition, we performed cell viability assays across a broad concentration range for two FDA-approved ALK inhibitors (crizotinib and ceritinib) in three prostate cancer cell lines as well as the lung cancer cell line H2228, which harbors an EML4-ALK fusion and the neuroblastoma cell line SH-SY5Y which has an ALK-activating mutation (6). The gene discussed is ALK; the disease is neuroblastoma.