MYCN

Troponin I is part of a heteromeric thin filament regulatory complex that is responsible for modulating skeletal and cardiac muscle contraction. Troponin complex consists of three subunits: troponin I (TnI), troponin T (TnT), and troponin C (TnC). Each of these subunits has a different role in the function of the complex. In particular, TnI is the inhibitory component, and confers calcium-sensitivity to the ATPase activity of the myofibril contractile apparatus within striated muscles. By blocking actin-myosin interactions, it regulates muscle relaxation.

The Ki67 antigen is a prototypic cell cycle-related protein expressed by proliferating cells in all phases of the active cell cycle (G1, S, G2 and M). It is a non-histone nuclear protein originally identified in a Hodgkin's lymphoma-derived cell line. Ki67 interacts with KIF15 and MKI67IP, and is approximately 395 kD. It exhibits a complex nuclear localization pattern that is cell cycle-dependent - expression peaks during late G1, S, G2, and M phases, but is undetectable in G0.