This study is designed to test how well two new **blood-based tests** can help detect cancer. Participants must be **45 years or older** and show signs or symptoms that suggest cancer. The study involves a simple **blood draw** for analysis. If you have suspected cancer, your regular doctor will continue to manage your care, and the study won't influence any treatment decisions. **Key Points:** - **Participation requires at least one blood draw.** - **No new treatments or changes to existing care are involved.** - **Participants must not have had any previous invasive cancers, except for certain types of skin cancer.** Eligibility includes providing consent and either undergoing diagnostic tests for cancer or having a recent cancer diagnosis without starting treatment. Exclusion criteria include having a fever, being pregnant, or recent involvement in other studies or treatments that could interfere.