LL-37, which is also known as cathelicidin. Chemically, it is a peptide, i.e., a short sequence of amino acids (AA), which is made up of only 37 amino acids. Its particular sequence of AA (also called the primary structure) is illustrated in Figure 1. As you can see in Figure 1, its primary structure has two leucine residues and “L” is the alphabetical representation of leucine, therefore it is named as LL-37 (Yang et al., 2020). LL-37 has anti-microbial properties against a broad spectrum of pathogenic microbes, like, bacteria (both, gram positive and negative), viruses and fungi (Turner et al., 1998). It is naturally synthesized in the body, upon the microbial invasion (Chen et al., 2018). It links the two major domains of the immune system, i.e., innate and adaptive. It does so by employing the cells of immune system at the site of infection, and thereby stimulating only the specific receptors on these cells. As it regulates the expression of both distinct types of inflammatory cytokines, i.e., pro- and anti-, normal expression and activity of LL-37 is not only essential but critical to normal physiology of the body.

Staurosporine (Str) (GC15299) is an alkaloid, which has a complex molecular structure comprising of nine fused rings. Its structure is diagrammatically depicted in Figure 1. It is primarily classified as a derivative of Indolocarbazole (Toledo and Lydon).