Human telomerase reverse transcriptase alone has been found to immortalise normal human astrocytes (Sonoda et al, 2001) with the addition of SV40 T-Ag and active Ras (H-ras), allowing maximum tumourigenicity as determined by anchorage-independent growth and formation of tumours in nude mice (Rich et al, 2001). Here, HRAS is linked to neoplasm.