It is possible that the hydrocortisone added to LTBMC medium [28] and/or IL-3 added weekly to the subculture medium may have facilitated activation of the K14 promoter linked E7 expression in hematopoietic cells from K14E7 Fancd2−/− and K14E7 Fand2+/+ mice; however, the Fancd2−/− genotype was clearly required for malignant transformation of hematopoietic cells to plasmacytomas. Here, IL3 is linked to plasmacytoma.