THY1 and thymoma: Thy-1–integrin interaction in trans was originally described in vitro in 2001, as the association of astrocytes containing αvβ3 integrin with a Thy-1+/+-thymoma cell line (EL-4), but not with Thy-1−/−- EL-4−f cells, (Leyton, Schneider et al., 2001).