I think it is best to include the names of all the research projects you are involved in, even if you are not leading them. You could mention in brackets that these projects are led by your Professor and you are part of the research team. While disclosing conflicts of interest (COI), it is always better to include whatever you are unsure about than run the risk of not disclosing a potential COI. Another option would be to send an inquiry to the editor explaining that you are unsure about whether to include these research projects, and wait for his/her answer.
- Conflicts of interest and journal disclosure policies: what every author should know
- How to identify and deal with conflicts of interest in research publication
- Failure to disclose potential conflict of interest lands author in trouble: A case study