The staining profiles with anti-CD90 Ab and PI showed that the CD90−/PI+ fraction and a ratio of the CD90−PI+ populations to all the CD90− cells increased when the tumour cells were cultured with Ad/IFN-λ2-infected P6X cells compared with the co-culture cases with uninfected or Ad/LacZ-infected P6X cells (Table 3). Here, THY1 is linked to neoplasm.