Titin (TTN) is a giant spring-like protein that contributes to the mechanical properties of cardiomyocytes and affects cardiac function in heart disease. The TTN gene has >360 exons and is subject to extensive alternative splicing. The aim of the project is to study splicing of TTN in heart failure patients with various underlying heart disease and non-failing controls. We have generated RNA-sequencing data from 109 cardiac tissue samples (102 patients across 10 subgroups and 7 controls). We want to compare exon usage across the TTN gene between patients and controls, as well as between patient subgroups, using the DEXSeq package.