In this video from the Koch Institute at MIT, you can see work that won an Image Award for 2017. The image was generated by Dahlia Perez of the Lees lab, who explains her research. The lab studies how chemical cascades or pathways function in normal biology, and how they go wrong in disease. This picture is a part of an investigation of melanoma in a zebrafish model.
Zebrafish have cells called melanocytes that are pigmented with melanin. These cells are seen in the image in black along with another type of pigmented cell that is yellow. These cell types give zebrafish their coloration. The melanocytes are also the origin of melanoma.
There are two types of genetic mutations associated with melanoma, one of the skin and one of the eye. But treatments for melanoma that impacts the skin don't work for that of the eye. The human mutations were put into the zebrafish genome (and designed to affect the melanocytes only), to observe the impacts. This work can help reveal more about how to treat different types of melanoma.