CDK4 and melanoma: Enthusiasm for the clinical testing of CDK4i/6i-containing therapy strategies in patients with other forms of melanoma has grown in the past decade stemming from (a) observations of CDK4-pathway alterations in >90% of CM cases, (b) evidence of downstream activation of CDK4/6 as a consequence of elevated MAPK pathway signaling, and (c) a role for CDK4 in ICB resistance [25].