TNNI3 and familial dilated cardiomyopathy: After this setback, the role of biallelic TNNI3 mutations in DCM remained uncertain until the late 2010s, when the progressively universal implementation in the clinical setting of high-throughput parallel sequencing approaches began to provide a slow but steady increase in case series, describing cardiomyopathy phenotypes in association with homozygous or compound heterozygous TNNI3 variants (Figure 3).