各位老师，刚刚开始学习R 不久，遇到这么一个问题，代码运行老是报错，不知道错误出在哪里,以下是程序：

uni_cox_in_bulk <- function(gene_list, survival_info_df){
  uni_cox <- function(single_gene){
    formula <- as.formula(paste('Surv(PFS, PFS_status)~', single_gene))
    surv_uni_cox <- summary(coxph(formula, data = df))
    ph_hypothesis_p <- cox.zph(coxph(formula, data = df))$table[1,3]
    if (surv_uni_cox$coefficients[,5]<0.05 & ph_hypothesis_p>0.05){ #get the pvalue
      single_cox_report <- data.frame('uni_cox_sig_genes'=single_gene,
      'beta'=surv_uni_cox$coefficients[,1],
      'Hazard_Ratio'=exp(surv_uni_cox$coefficients[,1]),
      'z_pvalue'=surv_uni_cox$coefficients[,5],
      'Wald_pvalue'=as.numeric(surv_uni_cox$waldtest[3]),
      'Likelihood_pvalue'=as.numeric(surv_uni_cox$logtest[3]))
      single_cox_report
   }
  }
  uni_cox_list <- lapply(gene_list, uni_cox)
  do.call(rbind, uni_cox_list)
}

uni_cox_df <- uni_cox_in_bulk(gene_list = gene_list, survival_info_df = df)

运行后报错为：Error in asgn[[ii]] : subscript out of bounds


请问哪位前辈知道这是错在哪里吗？非常感谢！