Tissue samples from patients with PDAC in the primary training cohort were divided into two groups based on the density of CD8+ T cells, CD133+ CSCs, or CK19+ TB as follows: a low-density CD8+ T cell group (CD8+ T cell count/mm2 ≤ 309.2) and a high-density CD8+ T cell group (CD8+ T cell count/mm2 > 309.2); a low-density CD133+ T cell group (CD133+ cell count/mm2 ≤ 131.6) and a high-density CD133+ cell group (CD133+ cell count/mm2 > 131.6); and a low-density TB group (TB count/mm2 ≤ 336.1) and a high-density TB group (TB count/mm2 > 336.1). Here, CD8A is linked to tuberculosis.