Validation of functional activity of KLF4 constructs in cHL cell lines by induction of specific target genes. A total of 2 × 10⁶ KMH2-KLF4-ER and L428-KLF4-ER cells were seeded in 10 mL of complete culture medium and treated with 200nM of 4-OHT at the same day. Twenty-four hours later, cells were harvested, and expression of CDKN1A, CCND2, and CDKN1C was assessed by quantitative PCR. Data represent relative mRNA expression (mean ± SD) calculated by the comparative C_t method. The relevant nontreated controls were used as comparators. RPL13A was used as reference gene. All measurements were made in triplicate.