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Guidance molecules act as cues by carrying information to receptive cells; administering this information which tells the cell and its entities how to properly align.^[1]. Slit proteins behave as such when working in axonal guidance during the development of the nervous system. Similarly, these proteins help to orchestrate the development of various networks of tissues throughout the body. This role, also described as cell migration, is the primary role of Slit when interacting with ROBO. It is most commonly found acting in neurons, endothelial cells and cancer cells.^[1].

Several studies have shown that the interaction of Slit with its receptors is crucial in regulating the processes involved with the formation of organs. As previously discussed, these interactions play a key role in cell migration. Not surprisingly then, this gene has been found expressed during the development of tightly regulated tissues, such as the heart, lungs, gonads, and ovaries. For example, in early development of the heart tube in Drosophila, Slit and two of its Robo receptors guide migrating cardioblasts and pericardial cells in the dorsal midline. ^[2] In addition, research on mice has shown that Slit3 and its interaction with Robo1 may be crucial to the development and maturation of lung tissue genesis. Similarly, the expression of Slit3 is upregulated when aligning airway epithelium with endothelium.^[1] Due to its regulating function in tissue development, absence or mutations in the expression of these genes can result in abnormalities of these tissues. Several studies in mice and other vertebrates has shown this deficit results in death almost immediately after birth.

The Slit2 protein has recently been discovered to be associated with the development of new blood vessels from pre-existing vessels, or angiogenesis. Recent research has debated on whether this gene inhibits or stimulates this process. There has been significant proof to conclude that both are true, depending on the context. It has been concluded that the role of Slit depends on which receptor it binds, the target cells, and/or other environmental factors.^[3] Slit2 has been implicated in promoting angiogenesis in mice (both in vitro and in vevo), in the human placenta^[3], and in tumorigenesis.^[4]

Due to its pivotal role in controlling cell migration, abnormalities or absences in the expression of Slit1, Slit2 and Slit3 are associated with a variety of cancers. In particular, Slit-Robo interaction has been implicated in reproductive and hormone dependent cancers, particularly in females. Under normal function, these genes act as tumor suppressors. Therefore, deletion or lack of expression of these genes is associated with tumorigenesis, particularly tumors within the epithelium of the ovaries, endometrium, and cervix. Samples of surface epithelium in cancer ridden ovaries has exhibited that these cells show decreased expression of Slit2 and Slit3. In addition, absence of these genes allows the migration of cancer cells and thus is associated with increased cancer progression and increased metastasis^[2] . The role of this gene and its place in cancer treatment and development is becoming increasingly unraveled but increasingly complex.

Dickinson, Rachel; Duncan, Colin W. (April 2010). "The SLIT/ROBO pathway: a regulator of cell function with implications for the reproductive system". Reproduction. 139 (4): 697–704. doi:10.1530/REP-10-0017. PMC 2971463. PMID 20100881. 10.1530/REP-10-0017.{{cite journal}}: CS1 maint: date and year (link) CS1 maint: multiple names: authors list (link)