Figure 1. Unsupervised hierarchical cluster analysis of genes and experiments of 9 normal genital skin fibroblast lines (penile foreskin) and 5 AIS genital skin fibroblast lines (labia majora). Only transcripts whose log2 red / green ratio differed from the mean expression level across all ex-periments by at least 1.1 in at least three experiments are displayed (620 cDNAs). The dendrogram of the array experiments reflects the similarity of the samples with respect to their gene expression patterns. F = female external genitalia, M = normal male external genitalia, NORM = normal male control, AIS4 = AIS with predominantly female phenotype (slight enlargement of the clitoris), CAIS = complete androgen insensitivity syndrome. Increasing red intensity cor-responds to increased gene expression levels compared to the mean log2 red/green ratio for each gene; increasing green intensity corresponds to decreased gene expression levels. The scale ranges from -8 to +8 in log2 space.