Dr. Mark Joseph Abalajon, or Toto as he is more commonly called, is a graduate of the UST Faculty of Medicine and Surgery, batch 2006. He then underwent Urologic Surgery Residency Training at the University of the Philippines-Philippine General Hospital from 2008-2013. After residency, he proceeded to Yonsei University Severance Hospital in Seoul South Korea, where he took up a 1-year fellowship training in Urologic Oncology and Robotic Urology. In 2016, he finished his fellowship in Retroperitoneal Laparoscopy and Robotic Urology at the University of Heidelberg, Germany under Professor Jens Rassweiler. Recognizing the lack of dedicated reconstructive urologists in the country, he traveled to Pune India to learn from the great Professor Sanjay Kulkarni. 

Upon coming back to the Philippines, he became part of the consultant staff of the University of Santo Tomas Hospital Section of Urology where he would later on become the Subsection Chief of Reconstructive Urology.  He would also become part of the consultant staff of both Victoriano Luna Medical Center and East Avenue Medical Center. In 2018, Toto joined forces with fellow reconstructive urologists Patrick Matias and Michael Chua to establish the Philippine Society of Genitourinary Reconstructive Surgeons (PhilGURS) under the guidance of Drs. David Bolong, Eduardo Gatchalian and Jun Dy.  Determined to spread the practice of reconstructive urology, he would travel to different parts of the Philippines to teach and perform urethroplasties. He organized multiple workshops on reconstructive urology with the help of the other PhilGURS pioneers and Dr. Paksi Satyagraha from Indonesia.  

The COVID pandemic provided the opportunity to use social media as a platform to widen his network. He became very good friends with prominent names in the international field like Dr. Dimitriy Nikolavsky from New York. It was Dr. Nikolavsky who introduced Toto to other giants of reconstructive urology. Both him and Toto were able to organize a number of very successful webinars and postgraduate courses that helped educate general urologists of basic reconstructive principles. What would follow was a rapid rise in the popularity of reconstructive urology in the Philippines, even catching the attention of not just residents-in-training but also the more senior consultants.  This culminated in 2019, when PhilGURS was recognized by the Philippine Urological Association as an official subspecialty society. This would be followed a year later by the induction of the first ever batch of PhilGURS fellows. In 2020, Dr. Abalajon was accepted as an active member of both the International Society of Reconstructive Urology (ISORU) and The Society of Genitourinary Reconstructive Surgeons (GURS). In November 2021, Dr. Abalajon was elected into the Board of Directors of GURS, the first Filipino ever to be voted into a major international urologic subspecialty society. Currently he also serves as the Vice President of PhilGURS and the Fellowship Program Director in Reconstructive Urology at the East Avenue Medical Center.