In the study of a gene-rich region of the X chromosome, Xp11.23-p11.22, Fisher et al. (1997) identified a novel locus consisting of 8 exons in a 12.5-kb interval between the A4 and the SYP loci. This gene, called LMO6, was predicted to encode a product of 407 amino acids with significant homology to proteins containing LIM domains, in particular, mouse testin. The LIM domain is a cysteine-rich sequence motif that binds zinc atoms to form a specific protein-binding interface in protein-protein interactions. Like testin, the LMO6 product contains 3 such domains. Using an RT-PCR approach, they were able to amplify a 450-bp product spanning exons 5 to 7 of the LMO6 transcript from lymphoblastoid RNA. This confirmed that the LMO6 locus is indeed transcribed and unlikely to be a pseudogene.