IL1B and cervical cancer: When compared to primary human keratinocytes, parallel performed transcriptional analysis in immortalized cells by quantitative RT-PCR (q-PCR) even revealed an approximately two to four fold up-regulation of the basal pro-IL-1β mRNA levels (see Discussion), while in the respective malignant cells CaSki, SiHa and HeLa (Fig. 1D) as well as in the HPV-negative cervical cancer cell line C-33 A (Fig. S1C), transcription was either strongly reduced or absent.