Marij Welters received her Ph.D. from the Free University Medical Centre in Amsterdam, The Netherlands. As a post-doc she was involved for three years in transplantation immunology at the Erasmus Medical Centre in Rotterdam. In 2000 she joined as a post-doc and later as senior researcher the department of Immunohematology and Blood Bank at the Leiden University Medical Centre (LUMC) in Leiden under the supervision of prof. dr. Cornelius J.M. Melief. Here she focussed on the development of the synthetic long peptide vaccine against the human papillomavirus type 16 (HPV16) both in preclinical and clinical setting. The main focus was vulva intraepithelial neoplasia and cervical cancer induced by HPV16. The immunomonitoring of the clinical trials using state-of-the art and complementary assays were and are performed in a dedicated laboratory and with trained personnel under her supervision.
Also since 2008 she is heavenly involved in the European-based CIMT immunoguiding working group (CIP), which aims to help establish high-quality immunomonitoring across the scientific field by supporting the concept of harmonization and promoting the technical validation of immunomonitoring assays. In 2010 she moved to the group of prof. dr. Sjoerd H. van der Burg at department of Medical Oncology from LUMC, again involved the immunomonitoring of clinical trials and where the research area was extended to other tumour types (head and neck carcinoma, ovarian cancer, lung cancer, melanoma) and immune cell types (including myeloid and regulatory cells). In 2011 she was appointed Head of the Immunomonitoring Laboratory from the department of Medical Oncology and recently (January 2017) she became Assistant Professor here. Not only is the immunomonitoring performed in tissue and blood samples for internally as well as externally initiated clinical trials, but also the immune landscape in the tumor is interrogated in depth to develop rationale for combined immunotherapy.