Using size exclusion chromatography, researchers isolated one fraction that was toxic to cardiomyocytes. Three crude toxic fractions with distinct activities were identified in this first fraction: CTF-alpha, beta and gamma. CTF-gamma toxicity was not specific to cardiac cells. CTF-alpha and beta were specifically toxic to cardiomyocytes but with distinct mechanisms: CTF-alpha acted faster and at a lower dose than CTF-beta, but cell recovery was observed with a low dose of CTF-alpha, which was not the case for CTF-beta.