%A Pradeu,Thomas %A Cooper,Edwin %D 2012 %J Frontiers in Immunology %C %F %G English %K danger,danger signals,Immunity,Inflammation,innate immunity,Cancer,tolerance,Transplantation %Q %R 10.3389/fimmu.2012.00287 %W %L %M %P %7 %8 2012-September-17 %9 Hypothesis and Theory %+ Prof Thomas Pradeu,Sorbonne University,Philosophy,1 rue Victor Cousin,Paris,75005,France,thomas.pradeu@u-bordeaux.fr %# %! Danger theory %* %< %T The danger theory: 20 years later %U https://www.frontiersin.org/articles/10.3389/fimmu.2012.00287 %V 3 %0 JOURNAL ARTICLE %@ 1664-3224 %X The self–non-self theory has dominated immunology since the 1950s. In the 1990s, Matzinger and her colleagues suggested a new, competing theory, called the “danger theory.” This theory has provoked mixed acclaim: enthusiasm and criticism. Here we assess the danger theory vis-à-vis recent experimental data on innate immunity, transplantation, cancers and tolerance to foreign entities, and try to elucidate more clearly whether danger is well defined.