Combination Nilotinib and Paclitaxel in Adults With Relapsed Solid Tumors

Background: \- Researchers want to find better ways to treat cancer. One drug that treats cancer is paclitaxel. Sometimes proteins block that drug from working. Researchers want to see if another drug, nilotinib, helps paclitaxel work better. Objective: \- To test the safety of nilotinib plus paclitaxel and find out what doses of the drugs can be given safely to people. Eligibility: \- Adults at least 18 years old with advanced cancer that has progressed after receiving standard treatment, or for which no effective therapy exists. Design: * Participants will be screened with tests they usually get in their cancer care: medical history, physical exam, blood and urine tests, heart test, and scans. * Participants will take the two study drugs in 28-day cycles. They will keep a medicine diary. * Nilotinib will be taken by mouth twice every day except day 1 of the first cycle. * Paclitaxel will be given by IV once a week for the first 3 weeks of a cycle. This will usually be done at the clinic. * Most participants will have a weekly study visit every week for cycle 1, then the first 3 weeks of other cycles. They will have: * Physical exam at every visit. * Blood tests multiple times for cycle 1, then the first 3 weeks of other cycles. * Scans every 8 weeks. These may be CT or MRI scans, in a machine that takes pictures. Or they may be ultrasounds, where a wand is pressed on the skin with gel on it. * Around 30 days after stopping the study drugs, participants will be called to discuss any side effects.