TP73 and cancer: ΔNp73 and ΔN’p73 mRNAs are reported to be overexpressed in many cancers and are linked with poor prognosis42, but it is important to note that studies investigating ΔNp73 and other p73 N-terminal isoforms rely on highly sensitive PCR methods able to identify extremely low mRNA levels (for example ~ 10 copies in an entire sample reaction31, equivalent to less than 1 copy/100 cells).