CD55 and cervical carcinoma: qPCR of sorted GFP+ cells showed that KLF4 up-regulated CD55 mRNA levels 3.2-fold in Hela cells (Figure 3A left side), 7.7 -fold in the human cervical cancer cell line (C33-A) (Figure 3A right side) and 3-fold in HUVEC (Figure 3C).