HISTORY OF IMMUNOTHERAPY. PARADIGM CHANGE?: Born at the dawn of the 20th century with W.B. Coley's intratumoral injections of bacteria, cancer immunotherapy was built on the corpus of the immune surveillance theory in 1957, modified by R.D. Schreiber in 2004. Scientific knowledge and technological advances have allowed it to become efficacious and to expand in the 21st century as the 4th and most important pillar of cancer treatment.