CDKN2A and pharynx cancer: To further validate our in vitro results from primary HFK expressing E6/E7 genes, oro-pharyngeal cancer sections with known HPV status (as confirmed by two independent methods i.e. p16 staining and chromogenic in situ hybridisation (CISH)) were used to study the expression and localisation of p63, c-Jun, Src and MMP14.