For example, for NSCLC with LMD, current therapies target epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangement via tyrosine kinase inhibitors (TKIs); in breast cancer, HER2 positive disease may be targeted via an intrathecal injection; and finally, melanoma with BRAF V600E mutations may also be treated with targeted therapies. This evidence concerns the gene ALK and breast cancer.