GPA, Internships, and Grad Programs (Cancer Biology or Immunology)

[christy4310]

I am currently a senior and have started looking through different PhD programs. I've been concerned lately because I happen to have 2 C's (Organic Chem I and Physics I) and I worry about whether this will hold me back. I'm already taking an extra year (2020-2021) to complete my B.S. as well as continuing my research project and I prefer not to go into a Master's program as I am sure that I want to enter a PhD program. Should I be worried about my GPA (overall GPA: 3.5, major GPA: 3.3). Also to improve my chances, I have been considering applying to summer undergraduate research programs (internships), but I also figured that if I didn't do the summer programs I would just work on my year long project. Would grad programs prefer a summer internship where I would be able to participate in intensive research with a faculty member and present my research or continue working on a research project at my institution with my PI and eventually present my research that summer/year? 

Also, since I'm trying to refine my list of schools, what PhD programs are recommended for Cancer Biology or Immunology. My research interests include: Ovarian Cancer, HPV, Infectious Diseases, Allergy/Immunology Regulation