Abstract: The invention encompasses methods and reagents for the diagnosis of a disease caused by or associated with a gene having a somatic mutation giving rise to a frameshift mutation. The methods include the steps of providing a body fluid or tissue sample from a patient; and analyzing the sample for the presence of a gene having a frameshift mutation or a protein encoded thereby, wherein the presence of the mutated gene or encoded protein is indicative of the disease.

Abstract: Expression systems which comprise a mammalian host, such as erythroid cells, transformed with a vector which comprises a promoter, a DNA sequence which codes for a desired polypeptide and a dominant control region. The vectors and methods for preparing polypeptides using the expression systems are also described. In a preferred embodiment, the vector contains cDNA for the desired polypeptide and a sequence which is capable of stabilising mRNA produced from the cDNA. The expression systems are particularly efficient and are capable of secreting the desired polypeptide.

Abstract: Vectors for the integration of a gene into genetic material of a mammalian host cell such that the gene may be expressed by the host cell comprise a promoter and the gene and include a dominant ectivator sequence capable of eliciting host cell-type restricted, integration site independent, copy number dependent expression of the gene.