This study aims to determine if it is feasible to collect samples of blood and viable lung cancer tissue in patients with either: * Stage IV mutation-driven NSCLC * Stage II-III NSCLC undergoing neoadjuvant immunotherapy prior to surgery Viable tissue has been defined by the collaborating pathology department as the presence of viable tumour cells, in accordance with recommendations from the International Association or the Study of Lung Cancer. In patients with stage IV NSCLC, obtaining adequate samples of viable tissue for advanced testing can be challenging, as sites of cancer that are accessible by biopsy are often small, and contain few viable cancer cells. If obtained, however, viable blood and tissue specimens can be utilised for genetic and other analyses aimed at identifying cancer markers that may offer prognostic information, or that may potentially lead to development of therapies that target these markers in the future. In patients with stage II-III NSCLC, the use of immunotherapy prior to surgery has been shown to affect the proportion of viable tumour tissue at the time of surgery, although this needs to be further studied. There is a need to better understand the genetic basis of these tumours to improve response rates to immunotherapy prior to surgery. The study will be open for four years in total. The first three years will consist of recruitment and participant follow up, and the fourth year will consist of follow up only. Data analysis will occur in the fifth year when the study is closed.