In our previous work (Kowalczyk et al. 2014), we explored the possibility that HSPA1A (+190G/C), HSPA1B (+1267A/G), and HSPA1L (+2437T/C) gene polymorphisms might be involved in the susceptibility to paranoid schizophrenia and clinical presentation of the disease in the Polish population. This evidence concerns the gene HSPA1L and schizophrenia.