RecruitingPhase 1Drug trial5-aza-4'-Thio-2'-Deoxycytidine (Aza-TdC) in People With Advanced Solid TumorsBackground: Blood, tissue, and tumor cells contain genes. Genes are made up of DNA. DNA is the "instruction book" for each cell. In some people with cancer, the genes that might have slowed the growth of their tumor were "turned off." Researchers want to see if a new drug can turn the genes back on and slow the tumor growth. The drug is called Aza-TdC. Objective: To test the safety of Aza-TdC, and to find out the dose of this drug that can be safely given to humans. Eligibility: People ages 18 and older who have advanced cancer that has gotten worse after standard treatment, or for which no effective therapy exists Design: Participants will be screened with: Medical history Blood and urine tests Scans to measure their tumors Test to measure the electrical activity of the heart Participants will take the study drug by mouth. The drug is given in cycles. Each cycle is 21 days (3 weeks) long. Week 1 and week 2: participants will take the study drug once a day for 5 days. Then they will have 2 days without the drug. Week 3: no study drug is taken. This completes one cycle of treatment. For cycle 1, participants will repeat the screening tests several times. For all other cycles, participants will have blood tests and pregnancy tests. They will have scans of their tumor every 6 weeks. The cycle will be repeated as long as the participant tolerates the drug and the cancer is either stable or gets better. Sponsoring Institute: National Cancer Institute ...