Thus, the “fil rouge” of inflammation may be the hidden link between different diseases, such as myocarditis—as a possible early-stage arrhythmogenic cardiomyopathy—and rare systemic diseases under the umbrella of the “desmoplakin disease spectrum”, including dilated or non-dilated cardiomyopathy, chronic inflammatory cardiomyopathy, and ACM (Figure 3). This evidence concerns the gene DSP and myocarditis.