CDK4 and neuroblastoma: Our findings are in accordance with synergistic antitumoral effects of the MEKi and CDK4/6i in various other tumor cell models, including neuroblastoma [23], neuroendocrine prostate carcinoma [43], melanoma [28,44,45], colorectal cancer [24,25,46], pancreatic cancer [47], and NSCLC models [26].