PDCD1 and neoplasm: In the case of apoptotic mechanisms, this is probably due to the indirect nature of this effect: while cabozantinib has a direct effect on inducing apoptosis in tumour cells, PD1 inhibition indirectly promotes apoptosis through T-cell induced cytotoxicity on the tumour cells, i.e. eliciting the immune response that prevents the tumour immune evasion (Figure 2, Table 5).