The significant reduction in cell proliferation markers positivity, as well as in cell viability, after HER-2 inhibition and the subsequent resumption of proliferation upon drug withdrawal underscores the reversible nature of this dormancy state, which is consistent with previous reports on residual tumor cell (RTC) behavior following targeted therapy [5,7,11,33,34,35,36,37]. This evidence concerns the gene ERBB2 and neoplasm.