A study demonstrated that an increased copy number of cdkl4 in colorectal cancer was predictive of poorer patient survival.32 Varghese’s group reported that CDKL5 overexpression was associated with poor prognosis for patients with glioblastoma.33 The only study conducted on breast cancer showed that patients with upregulated CDKL2 expression had a significantly poorer survival rate compared with patients without this change.23 However, our results indicate that loss of CDKL2 was negatively correlated with patient survival. The gene discussed is CDKL4; the disease is breast cancer.