Puja Das conducted a biology investigatory project on gene therapy in the treatment of cancer under the supervision of her teacher Bilkis Barbhuiyan. The project report discusses gene therapy and how it relates to cancer, explaining that gene mutations can cause cancer and gene therapy aims to cure cancer by inserting normal genes or modifying genes. It also outlines several current approaches to gene therapy for cancer such as using recombinant DNA to boost the immune system's response to cancer, introducing drug-sensitivity genes to activate prodrugs selectively in tumor cells, and protecting bone marrow from chemotherapy using drug-resistance genes.