The Id1 transcript as determined by a combination of complementary DNA (cDNA)-based membrane array [31], RT-PCR on RNA isolated from formalin-fixed paraffin-embedded tissue [32], and microarray [33] suggests that Id1 expression is in fact decreased in prostate cancer: these results are clearly contradictory to the majority of protein expression studies as discussed above. The gene discussed is ID1; the disease is prostate cancer.