Some proteins are normally present in tissues/cell and they used to express for routine work of the cell. Here they are not marker proteins. However they used to be elevated due to chemical/drug treatment. Here they are marker proteins. The proteins that are elevated in chemical treatment have subunits (oligomers) like a, b, c, d, k, m, t, z etc depending upon the tissue however they exist as dimers and some as trimers due to their presence in the cytosol or membrane. The combination of the subunits may be homodimers or heterodimers. To various types of inducers multiple combinations of proteins exists (revealed by protein purification analysis) but it is not clear why these proteins are expressed due to variation of the chemical or drug. Even if single chemical is used, at every dose of time, the expression of subunits is variable. Some scientists used to say that it is due to the specificity of the inducer a specific protein will be expressed. For each type of inducer the expression of protein is variable. Assume that each subunit may have its own controllong elements for its expression . Please provide any best information on this type of expression or combination.