Hsp90 (heat shock protein 90) is a highly abundant and ubiquitous molecular chaperone which plays an important role in the folding of newly synthesized proteins or stabilizing and refolding denatured proteins after stress. Its expression is associated with many types of tumors including breast cancer, pancreatic carcinoma, human leukemia and others.

Several glycoprocessing enzymes and glycoreceptors have been recognized as important targets for therapeutic intervention. This concept has inspired the development of important classes of therapeutics, such as anti-influenza, anti-inflammatory, Gaucher’s disease, hepatitis and cancer drugs.

Glucocorticoids (GCs) are secreted from the adrenal gland in response to exposure to emotional and physiologic stressors and are responsible for modulating essential metabolic, cardiovascular, immune, and behavioral functions [1–3]. The glucocorticoid receptor (GR) belongs to a family of nuclear hormone receptors that are ligand-dependent transcription factors.

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1, cortisone reductase, HSD11B1, 11beta-hydroxysteroid dehydrogenase type 1,11beta-HSD1) is an enzyme that is involved in glucocorticoid regulation by catalyzing the conversion of inactive cortisone to its active form cortisol. These hormones regulate several physiological processes, and modulation of glucocorticoid action has been implicated as a potential treatment for a variety of diseases.

It is generally acknowledged that histamine is an important regulator of a plethora of (patho) physiological conditions and exerts its actions through the interaction with four histamine receptor subtypes. All these receptors belong to the family of heptahelical GPCR's and are considered as a promising molecular targets for drug development.

Post-translational modifications, such as acetylation or phosphorylation, play a crucial role in the regulation of gene transcription in eukaryotes. Different subtypes of histone acetyltransferases (HATs) catalyze the acetylation of histones on specific lysine residues. 

Liver X receptors (LXRs) are nuclear receptors that regulate the metabolism of cholesterol and bile acids. LXRs function as nuclear cholesterol sensors that are activated in response to elevated intracellular cholesterol levels in multiple cell types.

Classical histone deacetylases (HDACs classes I, II, and IV) are a promising novel class of epigenetic anti-cancer drug targets. Inhibition of histone deacetylases results in hyperacetylation of histones and modulates gene expression by creating an open chromatin state that leads to expression of previously silenced genes.

Histone methyltransferases are promising epigenetic drug targets. Several drugs that inhibit histone methyltransferases have been developed for anticancer therapy. DOT1L histone H3 methyltransferase methylates lysine 79 on histone H3 (H3K79), within the globular histone domain upon which DNA is wrapped.