Abstract: In the present invention are disclosed concatemers of concatenated expression cassettes and vectors that enable the synthesis of such concatemers. The concatemer comprises in the 5′→3′ direction a cassette of nucleotide sequence of the general formula [rs2-SP—PR—X-TR—SP-rs1]n wherein rs1 and rs2 together denote a functional restriction site, SP individually denotes a spacer of at least two nucleotide bases, PR denotes a promoter, capable of functioning in a cell, X denotes an expressible nucleotide sequence, TR denotes a terminator, and SP individually denotes a spacer of at least two nucleotide bases, and n>/=2, and wherein at least a first cassette is different from a second cassette. The main purpose of these concatemers is the controllable and co-ordinated expression of large numbers of heterologous genes in a single host.