In this activity, students perform the Kaplan-Meier survival analysis on raw data obtained from an experiment that explores the effect of overexpressing the Snakeskin (Ssk) protein on the lifespan of a population of fruit flies. This tight junction equivalent protein is expressed at higher levels than normal specifically in the gut and throughout the entire lifespan of the flies. Because aging guts are accompanied by both a mislocalization and a decrease in the expression levels of junctional proteins, including Ssk, it was hypothesized that overexpressing Ssk may lead to a healthier fly with a longer lifespan. This data will be analyzed in order to determine if there is a significant difference between the control flies in which no overexpression occurs and the experimental group in which Ssk is overexpressed.