MYC and cervical carcinoma: Bergsmedh et al., used H-ras/human c-myc-transfected rat fibroblasts as donor and mouse embryonic fibroblasts as recipient cells [28] while Gaiffe et al., [42] used human HPV-positive cervical cancer cells and human mesenchymal cells taken from an adult human after abdominoplasty as source and recipient cells respectively.