HSPG2 and melanoma: Although a PLC < 1,000/μL is widely used to define lymphopenia [17], this threshold has shown inconsistent results in ICI-treated patients: it has not been identified as a prognostic factor in melanoma cohorts [23], whereas in lung cancer cohorts it has been reported to be prognostic [24], and in our cohort, a PLC cutoff of 1,000/μL did not demonstrate prognostic value.