How to cure serious diseases which do harm to the health of human being such as tumor and virus infection by "precision medicine" is always a difficult problem and a research hotspot in the medical field. With the launch of "precision medicine" project, contemporary drug design has reached the new era, namely, "precise" targeted drug molecular design should be one of the key pillars of precision medicine. The structure-based rational drug design and the targeted drug delivery system are important aspects of the contemporary "precision drug design". Precise noncovalent interactions between ligands and proteins lay the theoretical foundations for structure-based rational drug design. The development of new synthetic methodologies provides a powerful tool for drug precise synthesis, focusing both on the identification of intrinsically novel reactions, as well as the discovery of improved methods for carrying out existing transformations. Chemical biology has a significant role to play in the discovery and validation of new therapeutic targets. Over the past few years, many sensitive and accurate probes based on small organic molecules have demonstrated considerable promise in "precision drug design" as they provide a chemoproteomic means to confirm and quantify target engagement and selectivity of small molecule drug candidates. In the viewpoint of medicinal chemistry, this review highlights recent advances made in contemporary molecular targeted drug design in the context of "precision medicine".

Contents
1 Introduction
2 Structure-based "precision drug design"
2.1 Target-specific drug design
2.2 Isoform-selective drug design
2.3 Drug design strategies to overcome drug resistance
3 Kinetic target-guided dynamic combina-toril chemistry
4 Precise noncovalent interactions between ligands and proteins
5 The development of new synthetic methodologies:late stage functionalization of drug-like molecules
6 Targeted drug precise delivery systems
6.1 Biomarker-based drug precise delivery systems
6.2 Microenvironment-based drug precise delivery systems
6.3 Drug precise delivery systems based on organ-specific enzymes
6.4 Organelle-targeted drug precise delivery systems:mitochondria
6.5 Photodynamic therapy
7 Probes:chemical biology tools for "precision drug design"
7.1 Peptides-based probes
7.2 H₂O₂ probes
7.3 H₂S probes
7.4 Thiol-mediated cleavable fluorescent probles
7.5 Fluoride probes
7.6 Cysteamine two-photon fluorescence probes
7.7 Photo-triggered probes
7.8 MAO-B-specific probes
7.9 Biotin-based probes and diagnostic reagents
8 Conclusions and outlook