Additional Study Information: The purpose of this clinical research study is to find out if an Investigational Drug, called LN-144/LN-145, is safe and beneficial in the treatment of participants with Metastatic Melanoma, or head and neck squamous cell carcinoma (HNSCC) when given in combination with a medication, named pembrolizumab (Keytruda), or in participants with non-small cell lung cancer (NSCLC), when LN-144/LN-145 is given alone as a single therapy. The LN-144/LN-145 Study drug is made up of specialized white blood cells called lymphocytes or T cells that are derived from your tumor after a small piece is obtained by surgical removal. This piece of your own tumor is sent to a centralized manufacturing facility where T cells that have infiltrated your tumor are isolated and grown to create the study drug LN-144/LN-145, which are infused back into your body.