CCR4 and cancer: An investigation on 13 widely used diverse cancer cell lines and seven finite and immortalized normal cell lines verified the suitability of 12 putative HKGs to conclude, after verification by four algorithmic methods, that the top five reference genes for both cancer cell lines and all cell lines were the same: HNRNPL (Heterogeneous Nuclear Ribonucleoprotein L), IPO8 (importin 8), PUM1 (pumilio RNA binding family member 1), SNW1 (SNW domain containing 1), and CNOT4 (CCR4-NOT transcription complex subunit 4) [75].